Merge pull request 'Milestone/m6 gamut stage0 cgats release' (#57) from milestone/m6-gamut-stage0-cgats-release into feat/31-about-help-chrome

Reviewed-on: #57

Packages/ICCeryCore/Sources/ICCeryCore/Argyll/ArgyllRunner.swift

@@ -1,10 +1,18 @@
 import Foundation
 
 /// Errors from `ArgyllRunner` executions.
-public enum ArgyllRunnerError: LocalizedError, Equatable {
+public enum ArgyllRunnerError: LocalizedError, Equatable, Sendable {
     case processFailed(code: Int32, logs: [String])
     case missingArtefact(String)
     case malformedManifest(String)
+    case instrumentDetectionFailed(String)
+    case chartreadFailed(String)
+    case averageFailed(String)
+    case colprofFailed(String)
+    case applycalFailed(String)
+    case iccgamutFailed(String)
+    case profcheckFailed(String)
+    case profcheckUnparseable
 
     public var errorDescription: String? {
         switch self {
@@ -14,6 +22,22 @@ public enum ArgyllRunnerError: LocalizedError, Equatable {
             return "Expected output file was not created: \(path)"
         case .malformedManifest(let reason):
             return "Failed to parse printtarg manifest: \(reason)"
+        case .instrumentDetectionFailed(let reason):
+            return "Instrument detection failed: \(reason)"
+        case .chartreadFailed(let reason):
+            return "Chartread failed: \(reason)"
+        case .averageFailed(let reason):
+            return "Averaging failed: \(reason)"
+        case .colprofFailed(let reason):
+            return "Profile creation failed: \(reason)"
+        case .applycalFailed(let reason):
+            return "Apply calibration failed: \(reason)"
+        case .iccgamutFailed(let reason):
+            return "Gamut extraction failed: \(reason)"
+        case .profcheckFailed(let reason):
+            return "Profile verification failed: \(reason)"
+        case .profcheckUnparseable:
+            return "Profile verification produced unparseable output"
         }
     }
 }
@@ -63,6 +87,7 @@ public struct ArgyllRunner: Sendable {
         let binaryURL = binaryResolver.resolve("targen")
         let processId = ProcessID.targen(cleanBasename)
 
+        await ensureNotRunning(id: processId)
         let events = processManager.events()
         try await processManager.runStreaming(
             id: processId,
@@ -97,6 +122,7 @@ public struct ArgyllRunner: Sendable {
         let binaryURL = binaryResolver.resolve("printtarg")
         let processId = ProcessID.printtarg(cleanBasename)
 
+        await ensureNotRunning(id: processId)
         let events = processManager.events()
         try await processManager.runStreaming(
             id: processId,
@@ -145,22 +171,42 @@ public struct ArgyllRunner: Sendable {
 
     // MARK: - Shared collection
 
+    /// Cancels any previous child with the same id and waits for it to
+    /// finalize, so `runStreaming` / `runCaptured` never sees a
+    /// `duplicateID` from a leftover process (#50, #52).
+    private func ensureNotRunning(id: String) async {
+        guard await processManager.isRunning(id) else { return }
+        await processManager.kill(id: id)
+        var attempts = 0
+        while await processManager.isRunning(id), attempts < 30 {
+            try? await Task.sleep(for: .milliseconds(100))
+            attempts += 1
+        }
+    }
+
     private struct CollectedRun {
         var exitCode: Int32?
         var stdout: String
+        var stderr: String
         var lines: [String]
     }
 
     /// Drains the event stream until this child's `exit` event.
     /// stdout is accumulated both per-line (logs) and verbatim (for
     /// the manifest parse — the pretty JSON needs its newlines).
+    ///
+    /// When `flushPartialLines` is `true`, a background `Task` flushes
+    /// unterminated output every 500 ms so tools like `colprof` that
+    /// print dots without newlines still produce log batches.
     private func collect(
         id processId: String,
         events: AsyncStream<ProcessEvent>,
-        onLogBatch: (@Sendable ([String]) -> Void)?
+        onLogBatch: (@Sendable ([String]) -> Void)?,
+        flushPartialLines: Bool = false
     ) async -> CollectedRun {
         var lines: [String] = []
         var stdout = ""
+        var stderr = ""
         var pendingBatch: [String] = []
         var exitCode: Int32?
         var lastFlush = Date()
@@ -172,6 +218,17 @@ public struct ArgyllRunner: Sendable {
             onLogBatch?(out)
         }
 
+        var dotFlushTask: Task<Void, Never>?
+        if flushPartialLines {
+            dotFlushTask = Task { [processManager] in
+                while !Task.isCancelled {
+                    try? await Task.sleep(for: .milliseconds(500))
+                    if Task.isCancelled { break }
+                    await processManager.flushPartialLine(id: processId)
+                }
+            }
+        }
+
         for await event in events {
             guard event.id == processId else { continue }
             switch event {
@@ -181,6 +238,7 @@ public struct ArgyllRunner: Sendable {
                 pendingBatch.append(line)
             case .stderr(_, let line):
                 lines.append(line)
+                stderr += line + "\n"
                 pendingBatch.append(line)
             case .error(_, let message):
                 lines.append("Error: \(message)")
@@ -202,6 +260,541 @@ public struct ArgyllRunner: Sendable {
                 break
             }
         }
-        return CollectedRun(exitCode: exitCode, stdout: stdout, lines: lines)
+
+        dotFlushTask?.cancel()
+        if let dotFlushTask {
+            _ = await dotFlushTask.value
+        }
+
+        return CollectedRun(exitCode: exitCode, stdout: stdout, stderr: stderr, lines: lines)
+    }
+
+    // MARK: - instlist (Stage 3 detection)
+
+    /// Runs `instlist` and returns the detected devices.
+    ///
+    /// The fork emits pretty-printed JSON; if that cannot be decoded a regex
+    /// fallback constrained to known instrument tokens is used.
+    public func detectInstruments() async throws -> [InstrumentDevice] {
+        let binaryURL = binaryResolver.resolve("instlist")
+        let processId = ProcessID.instlist
+
+        await ensureNotRunning(id: processId)
+        let events = processManager.events()
+        try await processManager.runStreaming(
+            id: processId,
+            binary: binaryURL,
+            arguments: [],
+            workingDirectory: nil
+        )
+
+        var accumulator = JSONAccumulator()
+        var stdout = ""
+        var stderr: [String] = []
+        var exitCode: Int32?
+
+        for await event in events {
+            guard event.id == processId else { continue }
+            switch event {
+            case .stdout(_, let line):
+                stdout += line + "\n"
+                _ = accumulator.feed(line: line)
+            case .stderr(_, let line):
+                stderr.append(line)
+            case .exit(_, let code):
+                exitCode = code
+            default:
+                break
+            }
+            if exitCode != nil { break }
+        }
+
+        if let data = accumulator.completeData ?? stdout.trimmingCharacters(in: .whitespacesAndNewlines).data(using: .utf8) {
+            if let devices = try? InstrumentParser.parse(String(data: data, encoding: .utf8) ?? stdout) {
+                return devices
+            }
+        }
+
+        if let code = exitCode, code != 0, stderr.isEmpty == false {
+            throw ArgyllRunnerError.instrumentDetectionFailed(stderr.joined(separator: "\n"))
+        }
+
+        // Final fallback: try to parse the raw stdout as a text document.
+        if let devices = try? InstrumentParser.parse(stdout) {
+            return devices
+        }
+
+        throw ArgyllRunnerError.instrumentDetectionFailed("Could not parse instlist output")
+    }
+
+    // MARK: - average (Stage 3 multi-pass finish)
+
+    /// Runs `average` to merge two or more pass snapshots into the canonical `.ti3`.
+    public func runAverage(
+        config: AverageConfig,
+        onLogBatch: (@Sendable ([String]) -> Void)? = nil
+    ) async throws -> URL {
+        let cwd = PathSecurity.resolveSafeCwd(config.workingDirectory)
+        let args = try AverageArgs.build(config: config)
+        let binaryURL = binaryResolver.resolve("average")
+        let processId = ProcessID.average(config.basename)
+
+        await ensureNotRunning(id: processId)
+        let events = processManager.events()
+        try await processManager.runStreaming(
+            id: processId,
+            binary: binaryURL,
+            arguments: args,
+            workingDirectory: cwd
+        )
+        let run = await collect(id: processId, events: events, onLogBatch: onLogBatch)
+
+        guard run.exitCode == 0 else {
+            throw ArgyllRunnerError.averageFailed("average exited with code \(run.exitCode ?? -1)")
+        }
+
+        let canonical = cwd.appendingPathComponent("\(config.basename).ti3")
+        guard FileManager.default.fileExists(atPath: canonical.path) else {
+            throw ArgyllRunnerError.missingArtefact(canonical.path)
+        }
+        return canonical
+    }
+
+    // MARK: - colprof (Stage 4)
+
+    /// Runs `colprof` streaming, collecting logs and classifying progress
+    /// until the profile is written.
+    public func runColprof(
+        config: ColprofConfig,
+        onLogBatch: (@Sendable ([String]) -> Void)? = nil
+    ) async throws -> URL {
+        let cleanBasename = try PathSecurity.sanitizeBasename(config.basename)
+        let cwd = PathSecurity.resolveSafeCwd(config.workingDirectory)
+        let args = try ColprofArgs.build(config: config)
+        let binaryURL = binaryResolver.resolve("colprof")
+        let processId = ProcessID.colprof(cleanBasename)
+
+        await ensureNotRunning(id: processId)
+        let events = processManager.events()
+        try await processManager.runStreaming(
+            id: processId,
+            binary: binaryURL,
+            arguments: args,
+            workingDirectory: cwd
+        )
+        let run = await collect(
+            id: processId,
+            events: events,
+            onLogBatch: onLogBatch,
+            flushPartialLines: true
+        )
+
+        guard run.exitCode == 0 else {
+            throw ArgyllRunnerError.colprofFailed(
+                "colprof exited with code \(run.exitCode ?? -1)"
+            )
+        }
+
+        // Argyll may produce `.icm` on Windows, but on macOS we expect `.icc`.
+        // `resolveProfile` checks `.icm` first, then `.icc`, matching #69.
+        guard let profileURL = ArtefactProbe.resolveProfile(
+            basename: cleanBasename,
+            cwd: cwd
+        ) else {
+            let defaultURL = cwd.appendingPathComponent("\(cleanBasename).icc")
+            throw ArgyllRunnerError.missingArtefact(defaultURL.path)
+        }
+        return profileURL
+    }
+
+    // MARK: - applycal (post-colprof calibration curve)
+
+    /// Embeds a `.cal` curve into an `.icc`/`.icm` profile.
+    ///
+    /// Runs `applycal` captured and performs an in-place replace via
+    /// `{input}.applycal.tmp` then `replaceItemAt`. On failure the tmp
+    /// file is removed and the original is left untouched. The UI must
+    /// never request `unapply` (#52).
+    public func runApplycal(
+        config: ApplycalConfig
+    ) async throws -> URL {
+        assert(!config.unapply, "runApplycal does not support unapply")
+
+        let inputURL = config.inputProfileURL
+        let cwd = inputURL.deletingLastPathComponent()
+        let binaryURL = binaryResolver.resolve("applycal")
+        let processId = ProcessID.applycal(inputURL.lastPathComponent)
+
+        let tmpURL = inputURL.appendingPathExtension("applycal.tmp")
+        let fm = FileManager.default
+
+        // Remove any stale tmp from a previous crash.
+        try? fm.removeItem(at: tmpURL)
+
+        await ensureNotRunning(id: processId)
+
+        let outputConfig = ApplycalConfig(
+            calibrationPath: config.calibrationPath,
+            inputProfileURL: inputURL,
+            outputProfileURL: tmpURL,
+            unapply: false
+        )
+        let outputArgs = try ApplycalArgs.build(config: outputConfig)
+
+        let result = try await processManager.runCaptured(
+            id: processId,
+            binary: binaryURL,
+            arguments: outputArgs,
+            workingDirectory: cwd
+        )
+
+        guard result.exitCode == 0, !Task.isCancelled else {
+            try? fm.removeItem(at: tmpURL)
+            if Task.isCancelled {
+                throw CancellationError()
+            }
+            throw ArgyllRunnerError.applycalFailed(
+                result.stderr.isEmpty
+                    ? "applycal exited with code \(result.exitCode)"
+                    : result.stderr
+            )
+        }
+
+        guard fm.fileExists(atPath: tmpURL.path) else {
+            throw ArgyllRunnerError.applycalFailed(
+                "applycal did not create temp profile"
+            )
+        }
+
+        let attrs = try? fm.attributesOfItem(atPath: tmpURL.path)
+        let size = attrs?[.size] as? UInt64 ?? 0
+        guard size >= 128 else {
+            try? fm.removeItem(at: tmpURL)
+            throw ArgyllRunnerError.applycalFailed(
+                "calibrated profile is too small (\(size) bytes)"
+            )
+        }
+
+        do {
+            if fm.fileExists(atPath: inputURL.path) {
+                _ = try fm.replaceItemAt(inputURL, withItemAt: tmpURL)
+            } else {
+                try fm.moveItem(at: tmpURL, to: inputURL)
+            }
+        } catch {
+            try? fm.removeItem(at: tmpURL)
+            throw ArgyllRunnerError.applycalFailed(error.localizedDescription)
+        }
+
+        return inputURL
+    }
+
+    // MARK: - iccgamut (post-colprof gamut mesh)
+
+    /// Extracts a `.gam` mesh from the finished profile.
+    public func runIccgamut(
+        config: IccgamutConfig,
+        onLogBatch: (@Sendable ([String]) -> Void)? = nil
+    ) async throws -> URL {
+        let profileURL = config.profileURL
+        let cwd = profileURL.deletingLastPathComponent()
+        let stem = profileURL.deletingPathExtension().lastPathComponent
+        let args = try IccgamutArgs.build(config: config)
+        let binaryURL = binaryResolver.resolve("iccgamut")
+        let processId = ProcessID.iccgamut(stem: stem)
+
+        await ensureNotRunning(id: processId)
+        let events = processManager.events()
+        try await processManager.runStreaming(
+            id: processId,
+            binary: binaryURL,
+            arguments: args,
+            workingDirectory: cwd
+        )
+        let run = await collect(id: processId, events: events, onLogBatch: onLogBatch)
+
+        guard run.exitCode == 0 else {
+            throw ArgyllRunnerError.iccgamutFailed(
+                "iccgamut exited with code \(run.exitCode ?? -1)"
+            )
+        }
+
+        let gamURL = cwd.appendingPathComponent("\(stem).gam")
+        guard FileManager.default.fileExists(atPath: gamURL.path) else {
+            throw ArgyllRunnerError.missingArtefact(gamURL.path)
+        }
+        return gamURL
+    }
+
+    // MARK: - profcheck (Stage 5 verification)
+
+    /// Verifies a profile against the canonical `.ti3`.
+    public func runProfcheck(
+        config: ProfcheckConfig,
+        onLogBatch: (@Sendable ([String]) -> Void)? = nil
+    ) async throws -> ProfcheckReport {
+        let cwd = config.ti3URL.deletingLastPathComponent()
+        let ti3Path = config.ti3URL.path
+
+        let iccURL = Self.resolveProfileForVerification(config.iccURL)
+        let config = ProfcheckConfig(ti3URL: config.ti3URL, iccURL: iccURL)
+
+        let args = try ProfcheckArgs.build(config: config)
+        let binaryURL = binaryResolver.resolve("profcheck")
+        let processId = ProcessID.profcheck(ti3Path: ti3Path)
+
+        await ensureNotRunning(id: processId)
+        let events = processManager.events()
+        try await processManager.runStreaming(
+            id: processId,
+            binary: binaryURL,
+            arguments: args,
+            workingDirectory: cwd
+        )
+        let run = await collect(id: processId, events: events, onLogBatch: onLogBatch)
+
+        guard run.exitCode == 0 else {
+            throw ArgyllRunnerError.profcheckFailed(
+                run.stderr.isEmpty
+                    ? "profcheck exited with code \(run.exitCode ?? -1)"
+                    : run.stderr
+            )
+        }
+
+        let output = (run.stdout + "\n" + run.stderr).trimmingCharacters(in: .whitespacesAndNewlines)
+        let report = ProfcheckParser.parse(output)
+        guard report.isValid else {
+            throw ArgyllRunnerError.profcheckUnparseable
+        }
+        return report
+    }
+
+    private static func resolveProfileForVerification(_ url: URL) -> URL {
+        let fm = FileManager.default
+        if fm.fileExists(atPath: url.path) { return url }
+        let alt = url.pathExtension.lowercased() == "icc"
+            ? url.deletingPathExtension().appendingPathExtension("icm")
+            : url.deletingPathExtension().appendingPathExtension("icc")
+        return fm.fileExists(atPath: alt.path) ? alt : url
+    }
+
+    // MARK: - chartread (Stage 3 interactive)
+
+    /// Runs `chartread` and returns an `AsyncStream` of typed events.
+    ///
+    /// Subscribe-before-spawn, prompt/row/log forwarding, and exit verification
+    /// are all handled here. Use `sendChartreadInput` to drive the child and
+    /// `cancelChartread` to terminate it.
+    public func runChartread(config: ChartreadConfig) -> AsyncStream<ChartreadEvent> {
+        let cleanBasename: String
+        let cwd: URL
+        do {
+            cleanBasename = try PathSecurity.sanitizeBasename(config.basename)
+            cwd = PathSecurity.resolveSafeCwd(config.workingDirectory)
+        } catch {
+            return AsyncStream { continuation in
+                continuation.yield(.failed(ArgyllRunnerError.chartreadFailed(error.localizedDescription)))
+                continuation.finish()
+            }
+        }
+
+        let args: [String]
+        do {
+            args = try ChartreadArgs.build(config: config)
+        } catch {
+            return AsyncStream { continuation in
+                continuation.yield(.failed(ArgyllRunnerError.chartreadFailed(error.localizedDescription)))
+                continuation.finish()
+            }
+        }
+
+        let binaryURL = binaryResolver.resolve("chartread")
+        let processId = ProcessID.chartread(cleanBasename)
+        let processManager = self.processManager
+        let isXY = config.isXY
+
+        return AsyncStream { continuation in
+            let task = Task {
+                await ensureNotRunning(id: processId)
+                let events = processManager.events()
+
+                // Register the XY parking hook before spawning.
+                await processManager.setPreKillHook(id: processId) { [processManager] in
+                    if isXY {
+                        try? await processManager.sendStdin(id: processId, bytes: ChartreadInput.quit.bytes)
+                        try? await Task.sleep(for: .milliseconds(500))
+                    }
+                }
+
+                do {
+                    try await processManager.runStreaming(
+                        id: processId,
+                        binary: binaryURL,
+                        arguments: args,
+                        workingDirectory: cwd
+                    )
+                } catch {
+                    continuation.yield(.failed(ArgyllRunnerError.chartreadFailed(error.localizedDescription)))
+                    continuation.finish()
+                    return
+                }
+
+                var state: ChartreadState = .idle
+                var pendingLogs: [String] = []
+                var lastFlush = Date()
+                var exitCode: Int32?
+
+                func flushLogs() {
+                    guard !pendingLogs.isEmpty else { return }
+                    let batch = pendingLogs
+                    pendingLogs.removeAll(keepingCapacity: true)
+                    continuation.yield(.log(batch))
+                }
+
+                for await event in events {
+                    guard event.id == processId else { continue }
+
+                    switch event {
+                    case .stdout(_, let line):
+                        let previous = state
+                        let classified = ChartreadClassifier.classify(line: line, previousState: previous)
+                        state = classified.state
+
+                        if classified.isRemoveSheetNotice {
+                            continuation.yield(.removeSheetNotice)
+                        }
+
+                        let shouldPrompt =
+                            classified.sheetNumber != nil
+                            || classified.alignmentPatch != nil
+                            || classified.requestedWarningKey != nil
+                            || classified.state != previous
+                            || classified.isTableContinuation
+
+                        if shouldPrompt {
+                            continuation.yield(.prompt(classified))
+                        }
+
+                        pendingLogs.append(line)
+
+                    case .stderr(_, let line):
+                        pendingLogs.append(line)
+
+                    case .jsonRow(_, let payload):
+                        do {
+                            let row = try JSONDecoder().decode(ChartreadRow.self, from: payload)
+                            state = row.isFinalRow ? .allStripsRead : state
+                            continuation.yield(.row(row))
+                        } catch {
+                            pendingLogs.append("Malformed row JSON: \(error.localizedDescription)")
+                        }
+
+                    case .error(_, let message):
+                        pendingLogs.append("Error: \(message)")
+
+                    case .exit(_, let code):
+                        exitCode = code
+                    }
+
+                    if exitCode == nil,
+                       pendingLogs.count >= 20 || Date().timeIntervalSince(lastFlush) >= 0.1 {
+                        flushLogs()
+                        lastFlush = Date()
+                    }
+
+                    if exitCode != nil {
+                        flushLogs()
+                        break
+                    }
+                }
+
+                if Task.isCancelled {
+                    continuation.finish()
+                    return
+                }
+
+                let canonical = cwd.appendingPathComponent("\(cleanBasename).ti3")
+                if let code = exitCode, code == 0 {
+                    if FileManager.default.fileExists(atPath: canonical.path) {
+                        continuation.yield(.completed(canonical))
+                    } else {
+                        continuation.yield(.failed(ArgyllRunnerError.missingArtefact(canonical.path)))
+                    }
+                } else {
+                    continuation.yield(.failed(ArgyllRunnerError.chartreadFailed("chartread exited with code \(exitCode ?? -1)")))
+                }
+                continuation.finish()
+            }
+
+            continuation.onTermination = { _ in
+                task.cancel()
+                Task {
+                    await processManager.kill(id: processId)
+                }
+            }
+        }
+    }
+
+    /// Send an exact input sequence to the running `chartread` child.
+    public func sendChartreadInput(basename: String, input: ChartreadInput) async throws {
+        let cleanBasename = try PathSecurity.sanitizeBasename(basename)
+        let processId = ProcessID.chartread(cleanBasename)
+        try await processManager.sendStdin(id: processId, bytes: input.bytes)
+    }
+
+    /// Terminate a running `chartread` child.
+    ///
+    /// The actual XY parking is handled by the pre-kill hook registered in
+    /// `runChartread`.
+    public func cancelChartread(basename: String, isXY: Bool = false) {
+        let cleanBasename = try? PathSecurity.sanitizeBasename(basename)
+        guard let cleanBasename else { return }
+        let processId = ProcessID.chartread(cleanBasename)
+
+        Task {
+            await processManager.kill(id: processId)
+        }
+    }
+}
+
+/// Events emitted by a running `chartread` session.
+public enum ChartreadEvent: Sendable {
+    /// Classified prompt / state update.
+    case prompt(ChartreadClassifyResult)
+    /// A decoded `ROW_COLORS_JSON` row.
+    case row(ChartreadRow)
+    /// A batched log chunk (stdout + stderr lines).
+    case log([String])
+    /// Informational "remove last sheet" notice.
+    case removeSheetNotice
+    /// Process exited with the given code.
+    case exit(Int32)
+    /// Successful completion with the canonical `.ti3` URL.
+    case completed(URL)
+    /// Failure (non-zero exit, missing artefact, spawn/parse error).
+    case failed(ArgyllRunnerError)
+}
+
+/// Exact bytes sent to `chartread` stdin.
+public enum ChartreadInput: Sendable {
+    case trigger    // " \n"
+    case accept     // "\n"
+    case done       // "d\n"
+    case quit       // "q\n"
+    case customKey(String)
+
+    public var bytes: Data {
+        switch self {
+        case .trigger:
+            return Data(" \n".utf8)
+        case .accept:
+            return Data("\n".utf8)
+        case .done:
+            return Data("d\n".utf8)
+        case .quit:
+            return Data("q\n".utf8)
+        case .customKey(let key):
+            return Data("\(key)\n".utf8)
+        }
     }
 }

Packages/ICCeryCore/Sources/ICCeryCore/CGATS/CGATSParser.swift

@@ -0,0 +1,372 @@
+import Foundation
+
+/// Errors that can occur while parsing CGATS-like data.
+public enum CGATSParseError: Error, Equatable {
+    case emptyFile
+    case missingBeginDataFormat
+    case missingEndDataFormat
+    case missingBeginData
+    case missingEndData
+    case missingNumberOfFields
+    case missingNumberOfSets
+    case unknownFieldName(String)
+    case malformedRow(line: Int, reason: String)
+    case nonNumericValue(field: String, value: String, line: Int)
+    case outOfBoundsValue(field: String, value: Double, line: Int)
+    case implausibleValue(field: String, value: Double, line: Int)
+    case incorrectArity(line: Int, expected: Int, got: Int)
+}
+
+/// One row of a CGATS dataset, keyed by canonical field name.
+public struct CGATSSample: Sendable, Equatable {
+    public var id: String
+    public var loc: String?
+    public var values: [String: String]
+
+    public init(id: String, loc: String? = nil, values: [String: String] = [:]) {
+        self.id = id
+        self.loc = loc
+        self.values = values
+    }
+}
+
+/// A parsed CGATS / CTI3 / CSV dataset.
+public struct CGATSDataset: Sendable, Equatable {
+    public var format: CGATSFormat
+    public var keywords: [String: String]
+    public var fieldNames: [String]
+    public var samples: [CGATSSample]
+    public var colorRep: String?
+    public var deviceClass: String?
+    public var targetInstrument: String?
+
+    public init(
+        format: CGATSFormat,
+        keywords: [String: String] = [:],
+        fieldNames: [String] = [],
+        samples: [CGATSSample] = [],
+        colorRep: String? = nil,
+        deviceClass: String? = nil,
+        targetInstrument: String? = nil
+    ) {
+        self.format = format
+        self.keywords = keywords
+        self.fieldNames = fieldNames
+        self.samples = samples
+        self.colorRep = colorRep
+        self.deviceClass = deviceClass
+        self.targetInstrument = targetInstrument
+    }
+}
+
+public enum CGATSFormat: String, Sendable, Equatable {
+    case cti3 = "CTI3"
+    case cgats17 = "CGATS.17"
+    case csv = "CSV"
+}
+
+/// Parser for CGATS.17, CTI3, ISO28178, and simple CSV datasets.
+public enum CGATSParser {
+
+    /// Parse the contents of a CGATS-like file.
+    public static func parse(
+        _ contents: String,
+        sourceURL: URL? = nil
+    ) throws(CGATSParseError) -> CGATSDataset {
+        guard !contents.isEmpty else { throw .emptyFile }
+
+        let ext = sourceURL?.pathExtension.lowercased() ?? ""
+        let isCSV = ext == "csv" || contents.trimmingCharacters(in: .whitespacesAndNewlines)
+            .hasPrefix("SAMPLE_ID,")
+
+        let (format, lines) = try preprocess(contents, isCSV: isCSV)
+
+        var formatStart: Int?
+        var formatEnd: Int?
+        var dataStart: Int?
+        var dataEnd: Int?
+        var keywords = [String: String]()
+
+        for (index, line) in lines.enumerated() {
+            switch Self.normalizedKeyword(line) {
+            case "BEGIN_DATA_FORMAT": formatStart = index
+            case "END_DATA_FORMAT":   formatEnd = index
+            case "BEGIN_DATA":        dataStart = index
+            case "END_DATA":          dataEnd = index
+            default:
+                if let (key, value) = parseKeyword(line) {
+                    keywords[key] = value
+                }
+            }
+        }
+
+        guard let formatStart, let formatEnd, formatEnd > formatStart + 1 else {
+            throw .missingBeginDataFormat
+        }
+        guard let dataStart, let dataEnd, dataEnd > dataStart + 1 else {
+            throw .missingBeginData
+        }
+
+        let rawFieldNames = splitFields(lines[formatStart + 1])
+        let fieldNames = rawFieldNames.map { canonicalFieldName($0) }
+
+        if let numberOfFields = keywords["NUMBER_OF_FIELDS"].flatMap(Int.init),
+           numberOfFields != fieldNames.count {
+            // Warn only; the data format line is the source of truth.
+        } else if keywords["NUMBER_OF_FIELDS"] == nil {
+            // Optional header; do not fail.
+        }
+
+        if let numberOfSets = keywords["NUMBER_OF_SETS"].flatMap(Int.init),
+           numberOfSets != dataEnd - dataStart - 1 {
+            // Warn only; the actual rows are the source of truth.
+        } else if keywords["NUMBER_OF_SETS"] == nil {
+            // Optional header; do not fail.
+        }
+
+        struct RawSample {
+            var id: String
+            var loc: String?
+            var numbers: [String: Double] = [:]
+            var strings: [String: String] = [:]
+            var lineIndex: Int
+        }
+
+        var rawSamples = [RawSample]()
+        var groupMax: [String: Double] = [:]
+
+        for offset in 1...(dataEnd - dataStart - 1) {
+            let lineIndex = dataStart + offset
+            let rawRow = splitFields(lines[lineIndex])
+            guard rawRow.count == fieldNames.count else {
+                throw .incorrectArity(line: lineIndex + 1, expected: fieldNames.count, got: rawRow.count)
+            }
+
+            var sample = RawSample(id: String(offset), lineIndex: lineIndex)
+            for (i, name) in fieldNames.enumerated() {
+                let raw = stripInlineComment(rawRow[i])
+                if isNumericField(name) {
+                    let cleaned = raw.trimmingCharacters(in: .whitespaces)
+                    if let number = parseNumber(cleaned) {
+                        sample.numbers[name] = number
+                        if let group = deviceGroup(name) {
+                            groupMax[group, default: 0] = max(groupMax[group, default: 0], number)
+                        }
+                    } else if !cleaned.isEmpty {
+                        throw .nonNumericValue(field: name, value: raw, line: lineIndex + 1)
+                    }
+                } else {
+                    sample.strings[name] = raw
+                }
+            }
+
+            sample.id = sample.strings["SAMPLE_ID"] ?? sample.numbers["SAMPLE_ID"].map { String(format: "%.0f", $0) } ?? String(offset)
+            sample.loc = sample.strings["SAMPLE_LOC"]
+            rawSamples.append(sample)
+        }
+
+        var samples = [CGATSSample]()
+        for raw in rawSamples {
+            var values = raw.strings
+            for (name, number) in raw.numbers {
+                var scaled = number
+                if let group = deviceGroup(name), let maxValue = groupMax[group], maxValue > 100 {
+                    scaled = number / 2.55
+                }
+                values[name] = validateValue(scaled, field: name, line: raw.lineIndex + 1)
+            }
+
+            var sample = CGATSSample(id: raw.id, loc: raw.loc, values: values)
+            // Keep lookups by canonical keys, but also preserve original aliases.
+            let rawRow = splitFields(lines[raw.lineIndex])
+            for (i, rawName) in rawFieldNames.enumerated() {
+                let canonical = canonicalFieldName(rawName)
+                if canonical != rawName {
+                    sample.values[rawName] = rawRow[i]
+                }
+            }
+            samples.append(sample)
+        }
+
+        let colorRep = keywords["COLOR_REP"] ?? inferColorRep(fieldNames: fieldNames)
+        let deviceClass = keywords["DEVICE_CLASS"] ?? inferDeviceClass(fieldNames: fieldNames)
+
+        return CGATSDataset(
+            format: format,
+            keywords: keywords,
+            fieldNames: fieldNames,
+            samples: samples,
+            colorRep: colorRep,
+            deviceClass: deviceClass,
+            targetInstrument: keywords["TARGET_INSTRUMENT"]
+        )
+    }
+
+    /// Parse from a URL (throws as `Error` for public callers).
+    public static func parse(url: URL) throws -> CGATSDataset {
+        let contents = try String(contentsOf: url)
+        return try parse(contents, sourceURL: url)
+    }
+
+    // MARK: - Internals
+
+    private static func preprocess(
+        _ contents: String,
+        isCSV: Bool
+    ) throws(CGATSParseError) -> (CGATSFormat, [String]) {
+        let allLines = contents.components(separatedBy: .newlines)
+        var lines = [String]()
+
+        var format: CGATSFormat?
+        for var line in allLines {
+            line = stripComment(line)
+            line = line.trimmingCharacters(in: .whitespaces)
+            guard !line.isEmpty else { continue }
+
+            if format == nil {
+                if line.hasPrefix("CTI3") { format = .cti3 }
+                else if line.hasPrefix("CGATS.17") { format = .cgats17 }
+                else if isCSV { format = .csv }
+            }
+
+            if line == "BEGIN_DATA_FORMAT" || line == "END_DATA_FORMAT" ||
+               line == "BEGIN_DATA" || line == "END_DATA" ||
+               (line.hasPrefix("BEGIN_DATA_FORMAT") || line.hasPrefix("END_DATA_FORMAT") ||
+                line.hasPrefix("BEGIN_DATA") || line.hasPrefix("END_DATA")) {
+                // These are exact keywords; keep them intact.
+            }
+
+            lines.append(line)
+        }
+
+        guard !lines.isEmpty else { throw .emptyFile }
+
+        // Wrap a bare CSV / ISO28178 file in the canonical CGATS block
+        // structure so the boundary-based parser below can handle it.
+        if let format, format == .csv,
+           !lines.contains(where: { Self.normalizedKeyword($0) == "BEGIN_DATA_FORMAT" }) {
+            let header = lines[0]
+            let data = lines.dropFirst()
+            lines = [
+                "CTI3",
+                "BEGIN_DATA_FORMAT",
+                header,
+                "END_DATA_FORMAT",
+                "BEGIN_DATA"
+            ] + Array(data) + [
+                "END_DATA"
+            ]
+            return (.csv, lines)
+        }
+
+        return (format ?? .cti3, lines)
+    }
+
+    private static func stripComment(_ line: String) -> String {
+        if let range = line.range(of: "#") {
+            return String(line[..<range.lowerBound])
+        }
+        return line
+    }
+
+    private static func stripInlineComment(_ token: String) -> String {
+        if let range = token.range(of: "#") {
+            return String(token[..<range.lowerBound]).trimmingCharacters(in: .whitespaces)
+        }
+        return token
+    }
+
+    private static func splitFields(_ line: String) -> [String] {
+        // CTI3/CGATS.17 use whitespace/tabs; CSV uses commas.
+        if line.contains(",") {
+            return line.components(separatedBy: ",").map { $0.trimmingCharacters(in: .whitespaces) }
+        }
+        return line.components(separatedBy: .whitespaces).filter { !$0.isEmpty }
+    }
+
+    private static func parseKeyword(_ line: String) -> (key: String, value: String)? {
+        // KEYWORD value  or  KEYWORD "value"
+        let tokens = splitFields(line)
+        guard let key = tokens.first else { return nil }
+
+        // Data-boundary keywords are not value keywords.
+        let boundaryKeys = Set([
+            "BEGIN_DATA_FORMAT", "END_DATA_FORMAT",
+            "BEGIN_DATA", "END_DATA"
+        ])
+        guard !boundaryKeys.contains(key) else { return nil }
+
+        let rawValue = tokens.dropFirst().joined(separator: " ")
+        let value = rawValue.trimmingCharacters(in: CharacterSet(charactersIn: "\""))
+        return (key, value)
+    }
+
+    private static func normalizedKeyword(_ line: String) -> String {
+        line.uppercased().trimmingCharacters(in: .whitespaces)
+    }
+
+    // MARK: - Field name normalization
+
+    private static func canonicalFieldName(_ raw: String) -> String {
+        let upper = raw.uppercased()
+            .replacingOccurrences(of: " ", with: "_")
+            .replacingOccurrences(of: "-", with: "_")
+        switch upper {
+        case "SAMPLE_ID", "ID": return "SAMPLE_ID"
+        case "SAMPLE_LOC", "LOC": return "SAMPLE_LOC"
+        case "SAMPLE_NAME": return "SAMPLE_ID"
+        case "LAB_L", "L*", "L_AB": return "LAB_L"
+        case "LAB_A", "A*", "A_AB": return "LAB_A"
+        case "LAB_B", "B*", "B_AB": return "LAB_B"
+        case "XYZ_X", "X": return "XYZ_X"
+        case "XYZ_Y", "Y": return "XYZ_Y"
+        case "XYZ_Z", "Z": return "XYZ_Z"
+        default: return upper
+        }
+    }
+
+    private static func isNumericField(_ name: String) -> Bool {
+        let numericNames: Set = [
+            "SAMPLE_ID", "SAMPLE_LOC", "SAMPLE_NAME"
+        ]
+        return !numericNames.contains(name)
+    }
+
+    private static func parseNumber(_ raw: String) -> Double? {
+        let formatter = NumberFormatter()
+        formatter.numberStyle = .decimal
+        return formatter.number(from: raw)?.doubleValue
+    }
+
+    private static func validateValue(_ value: Double, field: String, line: Int) -> String {
+        var number = value
+
+        // Plausibility checks for Lab and XYZ.
+        if field == "LAB_L" { number = max(0, min(160, number)) }
+        if field == "LAB_A" || field == "LAB_B" { number = max(-128, min(128, number)) }
+        if field.hasPrefix("XYZ_") { number = max(0, min(200, number)) }
+
+        return String(format: "%.4f", number)
+    }
+
+    private static func deviceGroup(_ name: String) -> String? {
+        if name.hasPrefix("RGB_") { return "RGB" }
+        if name.hasPrefix("CMYK_") { return "CMYK" }
+        if name.hasPrefix("DEVICE_") { return "DEVICE" }
+        return nil
+    }
+
+    private static func inferColorRep(fieldNames: [String]) -> String? {
+        if fieldNames.contains(where: { $0.hasPrefix("CMYK_") }) { return "CMYK" }
+        if fieldNames.contains(where: { $0.hasPrefix("RGB_") }) { return "RGB" }
+        if fieldNames.contains(where: { $0.hasPrefix("LAB_") }) { return "LAB" }
+        if fieldNames.contains(where: { $0.hasPrefix("XYZ_") }) { return "XYZ" }
+        return nil
+    }
+
+    private static func inferDeviceClass(fieldNames: [String]) -> String? {
+        if fieldNames.contains(where: { $0.hasPrefix("CMYK_") }) { return "PRINTER" }
+        if fieldNames.contains(where: { $0.hasPrefix("RGB_") }) { return "DISPLAY" }
+        return "OUTPUT"
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/CGATS/CGATSSummary.swift

@@ -0,0 +1,20 @@
+import Foundation
+
+/// Human-readable summary of an imported CGATS dataset.
+public struct CGATSSummary: Sendable, Equatable {
+    public let patchCount: Int
+    public let colorSpace: String?
+    public let deviceClass: String?
+    public let hasSpectral: Bool
+    public let previewRows: [String]
+
+    public init(dataset: CGATSDataset, previewRowCount: Int = 4) {
+        self.patchCount = dataset.samples.count
+        self.colorSpace = dataset.colorRep
+        self.deviceClass = dataset.deviceClass
+        self.hasSpectral = dataset.fieldNames.contains { $0.hasPrefix("SPECTRAL_") }
+        self.previewRows = Array(dataset.samples.prefix(previewRowCount).map { sample in
+            "\(sample.id)" + (sample.loc.map { " \($0)" } ?? "")
+        })
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/CGATS/CGATSWriter.swift

@@ -0,0 +1,82 @@
+import Foundation
+
+/// Errors from writing a canonical `.ti3` dataset.
+public enum CGATSWriterError: Error, Equatable {
+    case noSamples
+    case missingRequiredField(String)
+    case invalidValue(field: String, value: String)
+}
+
+/// Write a `CGATSDataset` to Argyll-consumable `.ti3` text.
+public enum CGATSWriter {
+
+    public static func write(_ dataset: CGATSDataset) throws -> String {
+        guard !dataset.samples.isEmpty, !dataset.fieldNames.isEmpty else {
+            throw CGATSWriterError.noSamples
+        }
+
+        var lines = [String]()
+
+        // Header
+        lines.append(dataset.format.rawValue)
+        lines.append("")
+
+        lines.append("DESCRIPTOR \"ICCery CGATS export\"")
+        if let colorRep = dataset.colorRep {
+            lines.append("COLOR_REP \"\(colorRep)\"")
+        }
+        if let deviceClass = dataset.deviceClass {
+            lines.append("DEVICE_CLASS \"\(deviceClass)\"")
+        }
+        if let instrument = dataset.targetInstrument {
+            lines.append("TARGET_INSTRUMENT \"\(instrument)\"")
+        }
+
+        lines.append("NUMBER_OF_FIELDS \(dataset.fieldNames.count)")
+        lines.append("NUMBER_OF_SETS \(dataset.samples.count)")
+        lines.append("")
+
+        lines.append("BEGIN_DATA_FORMAT")
+        lines.append(dataset.fieldNames.joined(separator: "\t"))
+        lines.append("END_DATA_FORMAT")
+        lines.append("")
+
+        lines.append("BEGIN_DATA")
+        for sample in dataset.samples {
+            let row = try dataset.fieldNames.map { field in
+                guard let raw = sample.values[field], !raw.isEmpty else {
+                    throw CGATSWriterError.missingRequiredField(field)
+                }
+                // Normalize numeric fields to a compact decimal.
+                if isNumeric(field) {
+                    return normalizedNumber(raw)
+                }
+                return raw
+            }
+            lines.append(row.joined(separator: "\t"))
+        }
+        lines.append("END_DATA")
+
+        return lines.joined(separator: "\n") + "\n"
+    }
+
+    public static func write(_ dataset: CGATSDataset, to url: URL) throws {
+        let text = try write(dataset)
+        try text.write(to: url, atomically: true, encoding: .utf8)
+    }
+
+    // MARK: - Internals
+
+    private static func isNumeric(_ field: String) -> Bool {
+        let nonNumeric: Set = ["SAMPLE_ID", "SAMPLE_LOC", "SAMPLE_NAME"]
+        return !nonNumeric.contains(field)
+    }
+
+    private static func normalizedNumber(_ raw: String) -> String {
+        guard let number = Double(raw) else { return raw }
+        if number == floor(number) {
+            return String(format: "%.0f", number)
+        }
+        return String(format: "%.4f", number)
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Files/ArtefactFiles.swift

@@ -15,14 +15,26 @@ public enum ArtefactFiles {
         try Data(contentsOf: url).base64EncodedString()
     }
 
-    /// `get_app_info` — version + build for the About dialog.
+    /// `get_app_info` — version, build, and build date for the About dialog.
     public static func appInfo(
         bundle: Bundle = .main
-    ) -> (version: String, build: String) {
+    ) -> (version: String, build: String, buildDate: String) {
         let info = bundle.infoDictionary ?? [:]
-        return (
-            info["CFBundleShortVersionString"] as? String ?? "0.0.0",
-            info["CFBundleVersion"] as? String ?? "0"
-        )
+        let version = info["CFBundleShortVersionString"] as? String ?? "0.0.0"
+        let build = info["CFBundleVersion"] as? String ?? "0"
+
+        let url = bundle.executableURL ?? bundle.bundleURL
+        let buildDate: String
+        if let values = try? url.resourceValues(forKeys: [.contentModificationDateKey]),
+           let date = values.contentModificationDate {
+            let formatter = DateFormatter()
+            formatter.dateStyle = .medium
+            formatter.timeStyle = .none
+            buildDate = formatter.string(from: date)
+        } else {
+            buildDate = "Unknown"
+        }
+
+        return (version, build, buildDate)
     }
 }

Packages/ICCeryCore/Sources/ICCeryCore/Measurement/AverageArgs.swift

@@ -0,0 +1,78 @@
+import Foundation
+
+/// Errors during `average` argv construction.
+public enum AverageArgError: LocalizedError, Equatable, Sendable {
+    case invalidBasename(String)
+    case invalidPassCount(Int)
+    case outputCollidesWithInput
+    case pathOutsideCwd(URL)
+
+    public var errorDescription: String? {
+        switch self {
+        case .invalidBasename(let name):
+            return "Invalid basename for average: \(name)"
+        case .invalidPassCount(let count):
+            return "Average requires at least 2 pass files, got \(count)"
+        case .outputCollidesWithInput:
+            return "Average output filename collides with one of the inputs"
+        case .pathOutsideCwd(let url):
+            return "Pass or output file is outside the working directory: \(url.path)"
+        }
+    }
+}
+
+/// Configuration for an `average` run.
+public struct AverageConfig: Sendable, Equatable {
+    public let workingDirectory: URL
+    public let basename: String
+    public let passFiles: [URL]
+
+    public init(
+        workingDirectory: URL,
+        basename: String,
+        passFiles: [URL]
+    ) {
+        self.workingDirectory = workingDirectory
+        self.basename = basename
+        self.passFiles = passFiles
+    }
+}
+
+/// Pure argv builder for Argyll's `average` tool.
+public enum AverageArgs {
+
+    /// Builds `average -v pass1 pass2 ... basename.ti3` with relative names.
+    public static func build(config: AverageConfig) throws -> [String] {
+        let cleanBasename = try PathSecurity.sanitizeBasename(config.basename)
+
+        guard config.passFiles.count >= 2 else {
+            throw AverageArgError.invalidPassCount(config.passFiles.count)
+        }
+
+        let output = config.workingDirectory
+            .appendingPathComponent("\(cleanBasename).ti3")
+
+        var inputNames: [String] = []
+        for url in config.passFiles {
+            try validate(url, isIn: config.workingDirectory)
+            inputNames.append(url.lastPathComponent)
+        }
+
+        try validate(output, isIn: config.workingDirectory)
+        let outputName = output.lastPathComponent
+
+        guard !inputNames.contains(outputName) else {
+            throw AverageArgError.outputCollidesWithInput
+        }
+
+        return ["-v"] + inputNames + [outputName]
+    }
+
+    private static func validate(_ url: URL, isIn cwd: URL) throws {
+        let cwdPath = cwd.standardizedFileURL.path
+        let urlPath = url.deletingLastPathComponent().standardizedFileURL.path
+        guard urlPath == cwdPath else {
+            throw AverageArgError.pathOutsideCwd(url)
+        }
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Measurement/ChartreadArgs.swift

@@ -0,0 +1,28 @@
+import Foundation
+
+/// Pure argv builder for Argyll's `chartread` tool.
+public enum ChartreadArgs {
+
+    /// Builds `chartread` argv per the Gronod fork protocol.
+    ///
+    /// - Always `-v -u`.
+    /// - `-c N` is emitted only for `selectedPort != nil` and `N > 1`.
+    /// - `-Y l` is emitted only when `enableLEDs` is `true`.
+    /// - Basename is the last positional argument and is sanitized.
+    public static func build(config: ChartreadConfig) throws -> [String] {
+        let cleanBasename = try PathSecurity.sanitizeBasename(config.basename)
+
+        var args: [String] = ["-v", "-u"]
+
+        if let port = config.selectedPort, port > 1 {
+            args.append(contentsOf: ["-c", "\(port)"])
+        }
+
+        if config.enableLEDs {
+            args.append(contentsOf: ["-Y", "l"])
+        }
+
+        args.append(cleanBasename)
+        return args
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Measurement/ChartreadClassifier.swift

@@ -0,0 +1,302 @@
+import Foundation
+
+/// Discrete states for the `chartread` interaction.
+public enum ChartreadState: String, Codable, Sendable, Equatable, CaseIterable {
+    case idle
+    case calibrating
+    case awaitingStrip
+    case reading
+    case allStripsRead
+    case warning
+    case promptContinue
+    case tablePlaceSheet
+    case tableAlign
+    case error
+    case finished
+}
+
+/// Extra metadata produced by classifying a single `chartread` stdout line.
+public struct ChartreadClassifyResult: Sendable, Equatable {
+    public let state: ChartreadState
+    /// Whether this line is an informational "remove last sheet" notice.
+    public let isRemoveSheetNotice: Bool
+    /// Parsed sheet index and total from "sheet N of M read ok" or "place sheet N of M".
+    public let sheetNumber: Int?
+    public let sheetTotal: Int?
+    /// Fiducial patch name from XY "locate patch X with the sight".
+    public let alignmentPatch: String?
+    /// When a warning asks for a specific key (e.g. `y` or `n`), the caller should send that key.
+    public let requestedWarningKey: String?
+    /// Whether the line is a continuation of a multi-line XY prompt.
+    public let isTableContinuation: Bool
+
+    public init(
+        state: ChartreadState,
+        isRemoveSheetNotice: Bool = false,
+        sheetNumber: Int? = nil,
+        sheetTotal: Int? = nil,
+        alignmentPatch: String? = nil,
+        requestedWarningKey: String? = nil,
+        isTableContinuation: Bool = false
+    ) {
+        self.state = state
+        self.isRemoveSheetNotice = isRemoveSheetNotice
+        self.sheetNumber = sheetNumber
+        self.sheetTotal = sheetTotal
+        self.alignmentPatch = alignmentPatch
+        self.requestedWarningKey = requestedWarningKey
+        self.isTableContinuation = isTableContinuation
+    }
+}
+
+/// Pure line classifier for `chartread` stdout.
+///
+/// Matchers are evaluated in strict priority order (docs/04 §3.5, docs/05 §12.6).
+/// XY table continuation lines stay sticky in `TABLE_PLACE_SHEET` / `TABLE_ALIGN`.
+public enum ChartreadClassifier {
+
+    private typealias Matcher = (String, ChartreadState) -> ChartreadClassifyResult?
+
+    public static func classify(
+        line: String,
+        previousState: ChartreadState
+    ) -> ChartreadClassifyResult {
+        let text = line.lowercased()
+
+        for matcher in matchers(previousState) {
+            if let result = matcher(text, previousState) {
+                return result
+            }
+        }
+
+        return ChartreadClassifyResult(state: previousState)
+    }
+
+    private static func matchers(_ previous: ChartreadState) -> [Matcher] {
+        [
+            removeSheetNotice,
+            sheetReadOk,
+            locatePatch,
+            placeSheet,
+            continuation(previous),
+            done,
+            warning,
+            calibration,
+            awaitingStrip,
+            reading,
+            error
+        ]
+    }
+
+    // 1. "Please remove last sheet from table" — info only.
+    private static func removeSheetNotice(text: String, previous: ChartreadState) -> ChartreadClassifyResult? {
+        guard text.contains("remove") && text.contains("last") && text.contains("sheet") else { return nil }
+        return ChartreadClassifyResult(state: previous, isRemoveSheetNotice: true)
+    }
+
+    // 2. "Sheet N of M read OK".
+    private static func sheetReadOk(text: String, previous: ChartreadState) -> ChartreadClassifyResult? {
+        guard let match = text.firstMatch(pattern: #"sheet\s+(\d+)\s+of\s+(\d+)\s+read\s+ok"#) else { return nil }
+        return ChartreadClassifyResult(
+            state: previous,
+            sheetNumber: match.1,
+            sheetTotal: match.2
+        )
+    }
+
+    // 3. "locate patch X with the sight".
+    private static func locatePatch(text: String, previous: ChartreadState) -> ChartreadClassifyResult? {
+        guard let match = text.firstMatch(pattern: #"locate\s+patch\s+([a-z0-9_]+)\s+with"#),
+              !match.0.isEmpty else { return nil }
+        return ChartreadClassifyResult(
+            state: .tableAlign,
+            alignmentPatch: match.0.uppercased()
+        )
+    }
+
+    // 4. "place sheet N of M" or "remove previous sheet".
+    private static func placeSheet(text: String, previous: ChartreadState) -> ChartreadClassifyResult? {
+        if let match = text.firstMatch(pattern: #"place\s+sheet\s+(\d+)\s+of\s+(\d+)"#) {
+            return ChartreadClassifyResult(
+                state: .tablePlaceSheet,
+                sheetNumber: match.1,
+                sheetTotal: match.2
+            )
+        }
+        if text.contains("remove previous sheet") || text.contains("place sheet") {
+            return ChartreadClassifyResult(state: .tablePlaceSheet)
+        }
+        return nil
+    }
+
+    // 5. "hit return to continue" — sticky if already in a table state.
+    private static func continuation(_ previous: ChartreadState) -> Matcher {
+        return { text, _ in
+            guard text.contains("hit return to continue")
+                    || text.contains("hit any key to continue")
+                    || text.contains("hit space to continue")
+            else { return nil }
+
+            if case .tablePlaceSheet = previous {
+                return ChartreadClassifyResult(state: .tablePlaceSheet, isTableContinuation: true)
+            }
+            if case .tableAlign = previous {
+                return ChartreadClassifyResult(state: .tableAlign, isTableContinuation: true)
+            }
+
+            return ChartreadClassifyResult(state: .promptContinue, isTableContinuation: true)
+        }
+    }
+
+    // 6. Done / all read.
+    private static func done(text: String, previous: ChartreadState) -> ChartreadClassifyResult? {
+        let phrases = [
+            "'d' if/when done", "d to finish/save", "all strips/patches read",
+            "all strips read", "all patches read", "done reading",
+            "'d' to save", "press d to", "hit 'd'", "d to finish", "d to save"
+        ]
+        if phrases.contains(where: { text.contains($0) }) {
+            return ChartreadClassifyResult(state: .allStripsRead)
+        }
+        return nil
+    }
+
+    // 7. Warnings / prompts needing a key.
+    private static func warning(text: String, previous: ChartreadState) -> ChartreadClassifyResult? {
+        let lower = text
+        let warningSignals = [
+            "(warning)", "use it anyway", "seem to have read strip",
+            "unexpected response", "try again", "do you want to",
+            "abort ? - are you sure", "are you sure"
+        ]
+
+        let isWarningPrompt =
+            warningSignals.contains(where: { lower.contains($0) })
+            || lower.contains("(y/n)")
+            || lower.contains("'y' or 'n'")
+            || lower.contains("?")
+
+        guard isWarningPrompt else { return nil }
+
+        var key: String?
+        if lower.contains("(y/n)") || lower.contains("'y' or 'n'") {
+            // Default to asking the user; no automatic key.
+            key = nil
+        } else if lower.contains("'y'") || lower.contains("press y") || lower.contains("hit 'y'") {
+            key = "y"
+        } else if lower.contains("'n'") || lower.contains("press n") || lower.contains("hit 'n'") {
+            key = "n"
+        }
+
+        return ChartreadClassifyResult(state: .warning, requestedWarningKey: key)
+    }
+
+    // 8. Calibration / place reference / white / standard tile.
+    private static func calibration(text: String, previous: ChartreadState) -> ChartreadClassifyResult? {
+        let lowercased = text.lowercased()
+        let placeTokens = ["place", "reference", "white", "calibrat", "standard"]
+        let hasPlaceSheet = lowercased.contains("place sheet") || lowercased.contains("remove previous sheet")
+        let hasLocate = lowercased.contains("locate patch")
+
+        guard placeTokens.contains(where: { lowercased.contains($0) }),
+              !hasPlaceSheet,
+              !hasLocate
+        else { return nil }
+
+        if lowercased.contains("calibrat")
+            || lowercased.contains("white reference")
+            || lowercased.contains("white tile")
+            || lowercased.contains("standard tile")
+            || lowercased.contains("reference")
+            || lowercased.contains("tile")
+            || lowercased.contains("hit any key to continue")
+            || lowercased.contains("hit space to continue") {
+            return ChartreadClassifyResult(state: .calibrating)
+        }
+        return nil
+    }
+
+    // 9. Awaiting strip.
+    private static func awaitingStrip(text: String, previous: ChartreadState) -> ChartreadClassifyResult? {
+        let lowercased = text.lowercased()
+
+        // These are explicit, multi-word prompts; we deliberately do NOT
+        // match bare "read strip" so that error lines like
+        // "failed to read strip" or "error reading strip" fall through to
+        // the error matcher.
+        let phrases = [
+            "ready to read",
+            "hit any key to read",
+            "hit a key to read",
+            "hit space to read",
+            "hit [space] to read",
+            "press any key to read",
+            "press space to read",
+            "trigger instrument",
+            "start reading",
+            "read next strip"
+        ]
+
+        // Also permit "hit X to read strip Y" or "ready to read strip Z".
+        if lowercased.range(of: #"(hit|press).+to\s+read\s+strip"#, options: .regularExpression) != nil {
+            return ChartreadClassifyResult(state: .awaitingStrip)
+        }
+
+        guard phrases.contains(where: { lowercased.contains($0) }) else { return nil }
+        return ChartreadClassifyResult(state: .awaitingStrip)
+    }
+
+    // 10. Reading.
+    private static func reading(text: String, previous: ChartreadState) -> ChartreadClassifyResult? {
+        let lowercased = text.lowercased()
+        let phrases = ["reading strip", "reading sheet", "processing", "scanning", "reading..."]
+        guard phrases.contains(where: { lowercased.contains($0) }) else { return nil }
+        return ChartreadClassifyResult(state: .reading)
+    }
+
+    // 11. Error.
+    private static func error(text: String, previous: ChartreadState) -> ChartreadClassifyResult? {
+        let lower = text.lowercased()
+
+        // Avoid false positives from confirmation prompts and "no error" status.
+        guard !lower.contains("no error") else { return nil }
+        guard !lower.contains("(y/n)")
+              && !lower.contains("'y' or 'n'")
+              && !lower.contains("?")
+        else { return nil }
+
+        let phraseMatches = ["failed to read", "error reading", "too fast", "too slow", "misread"]
+        for phrase in phraseMatches {
+            if lower.contains(phrase) {
+                return ChartreadClassifyResult(state: .error)
+            }
+        }
+
+        // Whole-word "error" only — bare "failed" alone is not enough.
+        if lower.range(of: #"\berror\b"#, options: .regularExpression) != nil {
+            return ChartreadClassifyResult(state: .error)
+        }
+
+        return nil
+    }
+}
+
+private extension String {
+    func firstMatch(pattern: String) -> (String, Int, Int)? {
+        guard let regex = try? NSRegularExpression(pattern: pattern, options: .caseInsensitive),
+              let match = regex.firstMatch(in: self, options: [], range: NSRange(self.startIndex..., in: self))
+        else { return nil }
+
+        let groups: [String] = (1..<match.numberOfRanges).compactMap { i in
+            let r = match.range(at: i)
+            guard r.location != NSNotFound, let range = Range(r, in: self) else { return nil }
+            return String(self[range])
+        }
+
+        guard let first = groups.first else { return nil }
+        let ints = groups.compactMap { Int($0) }
+        let a = ints.count > 0 ? ints[0] : 0
+        let b = ints.count > 1 ? ints[1] : 0
+        return (first, a, b)
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Measurement/ChartreadConfig.swift

@@ -0,0 +1,45 @@
+import Foundation
+
+/// Errors during `ChartreadArgs` validation.
+public enum ChartreadArgError: LocalizedError, Equatable {
+    case invalidBasename(String)
+    case invalidPort(Int)
+
+    public var errorDescription: String? {
+        switch self {
+        case .invalidBasename(let name):
+            return "Invalid chart basename: \(name)"
+        case .invalidPort(let port):
+            return "Invalid chartread port: \(port)"
+        }
+    }
+}
+
+/// Configuration for a `chartread` invocation.
+public struct ChartreadConfig: Codable, Equatable, Sendable {
+    public var basename: String
+    public var workingDirectory: URL?
+    /// Communication port to pass to `chartread -c`.
+    /// `nil` means omit `-c` (Auto or port 1).
+    public var selectedPort: Int?
+    /// Enable i1Pro 2 visual LEDs (`-Y l`).
+    public var enableLEDs: Bool
+
+    public init(
+        basename: String,
+        workingDirectory: URL? = nil,
+        selectedPort: Int? = nil,
+        enableLEDs: Bool = false,
+        isXY: Bool = false
+    ) {
+        self.basename = basename
+        self.workingDirectory = workingDirectory
+        self.selectedPort = selectedPort
+        self.enableLEDs = enableLEDs
+        self.isXY = isXY
+    }
+
+    /// Whether the current config implies an XY-table workflow.
+    /// This is normally supplied by the view model from the selected instrument.
+    public var isXY: Bool = false
+}

Packages/ICCeryCore/Sources/ICCeryCore/Measurement/ChartreadRow.swift

@@ -0,0 +1,143 @@
+import Foundation
+
+/// A single patch read by `chartread`.
+public struct ChartreadPatch: Codable, Sendable, Equatable {
+    public let id: String
+    public let loc: String
+    public let isPad: Bool
+    public let device: [Double]
+    public let expected: PatchColor?
+    public let measured: PatchColor
+
+    public init(
+        id: String,
+        loc: String,
+        isPad: Bool,
+        device: [Double],
+        expected: PatchColor?,
+        measured: PatchColor
+    ) {
+        self.id = id
+        self.loc = loc
+        self.isPad = isPad
+        self.device = device
+        self.expected = expected
+        self.measured = measured
+    }
+
+    enum CodingKeys: String, CodingKey {
+        case id, loc
+        case isPad = "is_pad"
+        case device, expected, measured
+    }
+}
+
+/// Colour payload carried by `expected` or `measured`.
+public struct PatchColor: Codable, Sendable, Equatable {
+    public let xyz: CIEXYZ?
+    public let lab: CIELab?
+    public let spectral: SpectralData?
+
+    public init(xyz: CIEXYZ? = nil, lab: CIELab? = nil, spectral: SpectralData? = nil) {
+        self.xyz = xyz
+        self.lab = lab
+        self.spectral = spectral
+    }
+
+    enum CodingKeys: String, CodingKey {
+        case xyz = "XYZ"
+        case lab = "Lab"
+        case spectral = "spectral"
+    }
+}
+
+public struct CIEXYZ: Codable, Sendable, Equatable {
+    public let x: Double
+    public let y: Double
+    public let z: Double
+
+    public init(from decoder: Decoder) throws {
+        var container = try decoder.unkeyedContainer()
+        self.x = try container.decode(Double.self)
+        self.y = try container.decode(Double.self)
+        self.z = try container.decode(Double.self)
+    }
+
+    public init(x: Double, y: Double, z: Double) {
+        self.x = x
+        self.y = y
+        self.z = z
+    }
+
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.unkeyedContainer()
+        try container.encode(x)
+        try container.encode(y)
+        try container.encode(z)
+    }
+}
+
+public struct CIELab: Codable, Sendable, Equatable {
+    public let l: Double
+    public let a: Double
+    public let b: Double
+
+    public init(from decoder: Decoder) throws {
+        var container = try decoder.unkeyedContainer()
+        self.l = try container.decode(Double.self)
+        self.a = try container.decode(Double.self)
+        self.b = try container.decode(Double.self)
+    }
+
+    public init(l: Double, a: Double, b: Double) {
+        self.l = l
+        self.a = a
+        self.b = b
+    }
+
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.unkeyedContainer()
+        try container.encode(l)
+        try container.encode(a)
+        try container.encode(b)
+    }
+}
+
+public struct SpectralData: Codable, Sendable, Equatable {
+    public let bands: Int
+    public let startNM: Double
+    public let endNM: Double
+    public let norm: Double
+    public let values: [Double]
+
+    enum CodingKeys: String, CodingKey {
+        case bands
+        case startNM = "start_nm"
+        case endNM = "end_nm"
+        case norm
+        case values
+    }
+}
+
+/// A complete row emitted by `chartread -u`.
+public struct ChartreadRow: Codable, Sendable, Equatable {
+    public let event: String
+    public let rowId: String
+    public let rowIndex: Int
+    public let totalRows: Int
+    public let patchCount: Int
+    public let patches: [ChartreadPatch]
+
+    enum CodingKeys: String, CodingKey {
+        case event
+        case rowId = "row_id"
+        case rowIndex = "row_index"
+        case totalRows = "total_rows"
+        case patchCount = "patch_count"
+        case patches
+    }
+
+    public var isFinalRow: Bool {
+        rowIndex + 1 >= totalRows
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Measurement/ColorDifference.swift

@@ -0,0 +1,174 @@
+import Foundation
+
+/// Result of evaluating one measured patch.
+public struct SwatchEvaluation: Sendable, Equatable {
+    public let intended: DisplayRGB
+    public let measured: DisplayRGB
+    public let deltaE: Double?
+    public let classification: SwatchClassification
+
+    public init(
+        intended: DisplayRGB,
+        measured: DisplayRGB,
+        deltaE: Double?,
+        classification: SwatchClassification
+    ) {
+        self.intended = intended
+        self.measured = measured
+        self.deltaE = deltaE
+        self.classification = classification
+    }
+}
+
+public enum SwatchClassification: String, Sendable, Equatable, CaseIterable {
+    case good
+    case warning
+    case bad
+}
+
+/// CIEDE2000 ΔE₀₀ between two D50 Lab values.
+public enum ColorDifference {
+
+    /// Compute ΔE₀₀ using the full CIEDE2000 formula.
+    public static func deltaE00(_ lab1: LabColor, _ lab2: LabColor) -> Double {
+        let kL: Double = 1
+        let kC: Double = 1
+        let kH: Double = 1
+
+        let c1 = sqrt(lab1.a * lab1.a + lab1.b * lab1.b)
+        let c2 = sqrt(lab2.a * lab2.a + lab2.b * lab2.b)
+
+        let cBar = (c1 + c2) / 2.0
+        let cBar7 = pow(cBar, 7)
+        let g = 0.5 * (1 - sqrt(cBar7 / (cBar7 + pow(25, 7))))
+
+        let a1p = (1 + g) * lab1.a
+        let a2p = (1 + g) * lab2.a
+
+        let c1p = sqrt(a1p * a1p + lab1.b * lab1.b)
+        let c2p = sqrt(a2p * a2p + lab2.b * lab2.b)
+
+        let h1p = atan2ToDegrees(lab1.b, a1p)
+        let h2p = atan2ToDegrees(lab2.b, a2p)
+
+        let deltaLp = lab2.l - lab1.l
+        let deltaCp = c2p - c1p
+
+        var deltaHp: Double = 0
+        if c1p * c2p == 0 {
+            deltaHp = 0
+        } else {
+            let diff = h2p - h1p
+            if abs(diff) <= 180 {
+                deltaHp = diff
+            } else if diff > 180 {
+                deltaHp = diff - 360
+            } else {
+                deltaHp = diff + 360
+            }
+        }
+
+        let deltaHp2 = 2 * sqrt(c1p * c2p) * sin(deltaHp * .pi / 360.0)
+
+        let lBarp = (lab1.l + lab2.l) / 2.0
+        let cBarp = (c1p + c2p) / 2.0
+
+        var hBarp: Double
+        if c1p * c2p == 0 {
+            hBarp = h1p + h2p
+        } else {
+            if abs(h1p - h2p) <= 180 {
+                hBarp = (h1p + h2p) / 2.0
+            } else if h1p + h2p < 360 {
+                hBarp = (h1p + h2p + 360) / 2.0
+            } else {
+                hBarp = (h1p + h2p - 360) / 2.0
+            }
+        }
+
+        let t = 1
+            - 0.17 * cos(deg2rad(hBarp - 30))
+            + 0.24 * cos(deg2rad(2 * hBarp))
+            + 0.32 * cos(deg2rad(3 * hBarp + 6))
+            - 0.20 * cos(deg2rad(4 * hBarp - 63))
+
+        let dTheta = 30 * exp(-pow((hBarp - 275) / 25, 2))
+        let cBarp7 = pow(cBarp, 7)
+        let rc = 2 * sqrt(cBarp7 / (cBarp7 + pow(25, 7)))
+
+        let sl = 1 + (0.015 * pow(lBarp - 50, 2)) / sqrt(20 + pow(lBarp - 50, 2))
+        let sc = 1 + 0.045 * cBarp
+        let sh = 1 + 0.015 * cBarp * t
+
+        let rt = -sin(deg2rad(2 * dTheta)) * rc
+
+        let lTerm = deltaLp / (kL * sl)
+        let cTerm = deltaCp / (kC * sc)
+        let hTerm = deltaHp2 / (kH * sh)
+
+        return sqrt(
+            lTerm * lTerm
+            + cTerm * cTerm
+            + hTerm * hTerm
+            + rt * cTerm * hTerm
+        )
+    }
+
+    /// Classify a ΔE value against user thresholds.
+    public static func classify(deltaE: Double, goodMax: Double, warningMax: Double) -> SwatchClassification {
+        if deltaE < goodMax { return .good }
+        if deltaE < warningMax { return .warning }
+        return .bad
+    }
+
+    /// Evaluate a patch: compute intended/measured sRGB and ΔE if both Lab values are present.
+    public static func evaluate(
+        patch: ChartreadPatch,
+        goodMax: Double,
+        warningMax: Double
+    ) -> SwatchEvaluation? {
+        guard let measured = resolveLab(patch.measured) else { return nil }
+
+        let measuredRGB = LabColorMath.labToSRGB(measured)
+
+        if let expectedColor = patch.expected,
+           let expectedLab = resolveLab(expectedColor) {
+            let de = deltaE00(expectedLab, measured)
+            let intendedRGB = LabColorMath.labToSRGB(expectedLab)
+            return SwatchEvaluation(
+                intended: intendedRGB,
+                measured: measuredRGB,
+                deltaE: de,
+                classification: classify(deltaE: de, goodMax: goodMax, warningMax: warningMax)
+            )
+        } else {
+            // No reference: still render measured colour, no ΔE.
+            return SwatchEvaluation(
+                intended: measuredRGB,
+                measured: measuredRGB,
+                deltaE: nil,
+                classification: .good
+            )
+        }
+    }
+
+    /// Resolve a Lab from a `PatchColor`, computing it from XYZ when Lab is absent.
+    public static func resolveLab(_ color: PatchColor) -> LabColor? {
+        if let lab = color.lab {
+            return LabColor(l: lab.l, a: lab.a, b: lab.b)
+        }
+        guard let xyz = color.xyz else { return nil }
+        return LabColorMath.xyzToLab(XYZColor(x: xyz.x, y: xyz.y, z: xyz.z))
+    }
+
+    private static func atan2ToDegrees(_ y: Double, _ x: Double) -> Double {
+        let radians = atan2(y, x)
+        var degrees = radians * 180.0 / .pi
+        if degrees < 0 { degrees += 360 }
+        return degrees
+    }
+
+    private static func deg2rad(_ degrees: Double) -> Double {
+        degrees * .pi / 180.0
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Measurement/InstrumentModels.swift

@@ -0,0 +1,58 @@
+import Foundation
+
+/// A device discovered by the Argyll `instlist` fork.
+public struct InstrumentDevice: Codable, Sendable, Equatable, Identifiable {
+    public let port: Int
+    public let name: String
+    public let type: String
+
+    public init(port: Int, name: String, type: String) {
+        self.port = port
+        self.name = name
+        self.type = type
+    }
+
+    public var id: Int { port }
+
+    /// XY tables are identified by name or type matching the fork pattern.
+    public var isXY: Bool {
+        let combined = "\(name) \(type)".lowercased()
+        let pattern = #"/spectro\s?scan|i1io/"#
+        return combined.range(of: pattern, options: .regularExpression) != nil
+    }
+
+    /// Human-readable label shown in the picker.
+    public var displayName: String {
+        let xyTag = isXY ? " · XY Table" : ""
+        return "\(name) [\(type)]\(xyTag)"
+    }
+}
+
+/// The user’s choice for a chartread session.
+public enum InstrumentSelection: Sendable, Equatable {
+    /// Auto / first available port — `chartread` omits `-c`.
+    case auto
+    /// A concrete instrument.
+    case device(InstrumentDevice)
+
+    /// The value to pass to `chartread -c`.
+    /// `nil` means omit `-c` (port 1 and Auto both map to no flag).
+    public var chartreadPort: Int? {
+        switch self {
+        case .auto:
+            return nil
+        case .device(let device):
+            return device.port == 1 ? nil : device.port
+        }
+    }
+
+    /// Whether the current selection implies an XY table workflow.
+    public var isXY: Bool {
+        switch self {
+        case .auto:
+            return false
+        case .device(let device):
+            return device.isXY
+        }
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Measurement/InstrumentParser.swift

@@ -0,0 +1,72 @@
+import Foundation
+
+/// Errors from `instlist` output parsing.
+public enum InstrumentParserError: Error, Sendable, Equatable {
+    case malformedJSON
+    case missingDevices
+    case invalidPort
+}
+
+/// Parses the Argyll `instlist` stdout document.
+///
+/// Fork `instlist` emits pretty-printed JSON with the shape
+/// `{ "event": "instruments", "devices": [ { "port": 1, "name": "...", "type": "..." } ] }`.
+/// If JSON decoding fails, a constrained regex fallback is used.
+/// Only lines accepted by the fallback must also match known instrument tokens.
+public enum InstrumentParser {
+
+    /// Known instrument tokens used by the regex fallback.
+    public static let knownInstrumentPattern =
+        #"i1|ColorMunki|Spyder|spectro|Display|Huey|DTP|SpectroScan|Smile|Klein"#
+
+    /// Parse the complete `instlist` output.
+    public static func parse(_ output: String) throws -> [InstrumentDevice] {
+        let trimmed = output.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !trimmed.isEmpty else { return [] }
+
+        if let data = trimmed.data(using: .utf8),
+           let decoded = try? decodeJSON(data) {
+            return decoded
+        }
+
+        let regex = try? NSRegularExpression(
+            pattern: #"^(\d+)[\s:=]+'?([^'\n]+)'?(?:\s+on\s+'?([^'\n]+)'?)?"#,
+            options: [.caseInsensitive, .anchorsMatchLines]
+        )
+        var devices: [InstrumentDevice] = []
+        let range = NSRange(trimmed.startIndex..., in: trimmed)
+        let matches = regex?.matches(in: trimmed, options: [], range: range) ?? []
+
+        for match in matches {
+            guard let portString = substring(trimmed, range: match.range(at: 1)),
+                  let port = Int(portString), port > 0 else { continue }
+
+            let name = substring(trimmed, range: match.range(at: 2))?.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""
+            let type = substring(trimmed, range: match.range(at: 3))?.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""
+
+            let combined = "\(name) \(type)".lowercased()
+            guard combined.range(of: knownInstrumentPattern,
+                                 options: [.regularExpression, .caseInsensitive]) != nil,
+                  !name.isEmpty else { continue }
+
+            devices.append(InstrumentDevice(port: port, name: name, type: type))
+        }
+
+        return devices
+    }
+
+    private static func decodeJSON(_ data: Data) throws -> [InstrumentDevice] {
+        let output = try JSONDecoder().decode(InstlistOutput.self, from: data)
+        return output.devices
+    }
+
+    private static func substring(_ source: String, range: NSRange) -> String? {
+        guard range.location != NSNotFound, let r = Range(range, in: source) else { return nil }
+        return String(source[r])
+    }
+}
+
+private struct InstlistOutput: Decodable {
+    let event: String
+    let devices: [InstrumentDevice]
+}

Packages/ICCeryCore/Sources/ICCeryCore/Measurement/LabColor.swift

@@ -0,0 +1,184 @@
+import Foundation
+
+/// XYZ tristimulus values, stored in the 0–100 scale used by the Argyll fork.
+public struct XYZColor: Sendable, Equatable {
+    public let x: Double
+    public let y: Double
+    public let z: Double
+
+    public init(x: Double, y: Double, z: Double) {
+        self.x = x
+        self.y = y
+        self.z = z
+    }
+}
+
+/// CIELab value (D50).
+public struct LabColor: Sendable, Equatable {
+    public let l: Double
+    public let a: Double
+    public let b: Double
+
+    public init(l: Double, a: Double, b: Double) {
+        self.l = l
+        self.a = a
+        self.b = b
+    }
+}
+
+/// sRGB colour in 0–1 display space.
+public struct DisplayRGB: Sendable, Equatable {
+    public let r: Double
+    public let g: Double
+    public let b: Double
+
+    public init(r: Double, g: Double, b: Double) {
+        self.r = r
+        self.g = g
+        self.b = b
+    }
+
+    public var clamped: DisplayRGB {
+        DisplayRGB(r: min(1, max(0, r)), g: min(1, max(0, g)), b: min(1, max(0, b)))
+    }
+}
+
+/// Colour-space conversions used by the swatch grid.
+///
+/// All numeric paths are deterministic and avoid platform colour-management APIs.
+public enum LabColorMath {
+
+    // Reference white for D50 (0–100 scale).
+    static let d50White = (X: 96.4212, Y: 100.0, Z: 82.5188)
+
+    // Reference white for D65 (0–100 scale).
+    static let d65White = (X: 95.0489, Y: 100.0, Z: 108.8840)
+
+    // Bradford cone-response matrix and its inverse (XYZ -> LMS).
+    static let bradford = [
+        [ 0.8951,  0.2664, -0.1614],
+        [-0.7502,  1.7135,  0.0367],
+        [ 0.0389, -0.0685,  1.0296]
+    ]
+
+    static let bradfordInv = [
+        [ 0.9869929, -0.1470543,  0.1599627],
+        [ 0.4323053,  0.5183603,  0.0492912],
+        [-0.0085287,  0.0400428,  0.9684866]
+    ]
+
+    // sRGB D65 matrix (XYZ -> linear sRGB, using 0–100 inputs).
+    static let srgbMatrix = [
+        [ 3.2406, -1.5372, -0.4986],
+        [-0.9689,  1.8758,  0.0415],
+        [ 0.0557, -0.2040,  1.0570]
+    ]
+
+    /// Convert XYZ (0–100) to CIELab D50.
+    public static func xyzToLab(_ xyz: XYZColor) -> LabColor {
+        let f: (Double) -> Double = { t in
+            let delta = 6.0 / 29.0
+            if t > delta * delta * delta {
+                return pow(t, 1.0 / 3.0)
+            } else {
+                return t / (3 * delta * delta) + 4.0 / 29.0
+            }
+        }
+
+        let x = f(xyz.x / d50White.X)
+        let y = f(xyz.y / d50White.Y)
+        let zr = f(xyz.z / d50White.Z)
+
+        return LabColor(
+            l: 116.0 * y - 16.0,
+            a: 500.0 * (x - y),
+            b: 200.0 * (y - zr)
+        )
+    }
+
+    /// Convert CIELab D50 to XYZ (0–100).
+    public static func labToXYZ(_ lab: LabColor) -> XYZColor {
+        let finv: (Double) -> Double = { t in
+            let delta = 6.0 / 29.0
+            if t > delta {
+                return t * t * t
+            } else {
+                return 3 * delta * delta * (t - 4.0 / 29.0)
+            }
+        }
+
+        let yr = (lab.l + 16.0) / 116.0
+        let xr = yr + lab.a / 500.0
+        let zr = yr - lab.b / 200.0
+
+        return XYZColor(
+            x: finv(xr) * d50White.X,
+            y: finv(yr) * d50White.Y,
+            z: finv(zr) * d50White.Z
+        )
+    }
+
+    /// Convert XYZ D50 to XYZ D65 using the Bradford chromatic adaptation.
+    public static func adaptD50ToD65(_ xyz: XYZColor) -> XYZColor {
+        let source = matrixMultiply(bradford, [xyz.x, xyz.y, xyz.z])
+        let srcWhite = matrixMultiply(bradford, [d50White.X, d50White.Y, d50White.Z])
+        let dstWhite = matrixMultiply(bradford, [d65White.X, d65White.Y, d65White.Z])
+
+        let scaled = [
+            source[0] * (dstWhite[0] / srcWhite[0]),
+            source[1] * (dstWhite[1] / srcWhite[1]),
+            source[2] * (dstWhite[2] / srcWhite[2])
+        ]
+
+        return XYZColor(
+            x: scaled[0] * bradfordInv[0][0] + scaled[1] * bradfordInv[0][1] + scaled[2] * bradfordInv[0][2],
+            y: scaled[0] * bradfordInv[1][0] + scaled[1] * bradfordInv[1][1] + scaled[2] * bradfordInv[1][2],
+            z: scaled[0] * bradfordInv[2][0] + scaled[1] * bradfordInv[2][1] + scaled[2] * bradfordInv[2][2]
+        )
+    }
+
+    /// Convert XYZ D65 (0–100) to linear sRGB, apply gamma, and clamp.
+    public static func xyzToSRGB(_ xyz: XYZColor) -> DisplayRGB {
+        // sRGB matrix is defined for XYZ with D65 white at Y = 1.0.
+        // The input is 0–100, so scale by 100 first.
+        let scaled = [xyz.x / 100.0, xyz.y / 100.0, xyz.z / 100.0]
+        let linear = matrixMultiply(srgbMatrix, scaled)
+
+        func gamma(_ c: Double) -> Double {
+            if c <= 0.0031308 {
+                return 12.92 * c
+            } else {
+                return 1.055 * pow(c, 1.0 / 2.4) - 0.055
+            }
+        }
+
+        return DisplayRGB(
+            r: gamma(linear[0]),
+            g: gamma(linear[1]),
+            b: gamma(linear[2])
+        ).clamped
+    }
+
+    /// Complete D50 Lab -> display sRGB conversion.
+    public static func labToSRGB(_ lab: LabColor) -> DisplayRGB {
+        let xyz50 = labToXYZ(lab)
+        let xyz65 = adaptD50ToD65(xyz50)
+        return xyzToSRGB(xyz65)
+    }
+
+    /// Convert an Argyll XYZ array (0–100) to Lab and then to sRGB.
+    public static func xyzArrayToSRGB(_ xyz: [Double]) -> DisplayRGB? {
+        guard xyz.count >= 3 else { return nil }
+        return labToSRGB(xyzToLab(XYZColor(x: xyz[0], y: xyz[1], z: xyz[2])))
+    }
+
+    private static func matrixMultiply(_ m: [[Double]], _ v: [Double]) -> [Double] {
+        var result = [Double](repeating: 0, count: m.count)
+        for i in 0..<m.count {
+            for j in 0..<v.count {
+                result[i] += m[i][j] * v[j]
+            }
+        }
+        return result
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Measurement/MeasurementArtefacts.swift

@@ -0,0 +1,172 @@
+import Foundation
+
+/// Errors from pass-snapshot, promote, and discovery operations.
+public enum MeasurementArtefactError: LocalizedError, Equatable, Sendable {
+    case invalidBasename(String)
+    case canonicalMissing(URL)
+    case snapshotFailed(String)
+    case promoteFailed(String)
+    case noPassFiles
+
+    public var errorDescription: String? {
+        switch self {
+        case .invalidBasename(let name):
+            return "Invalid measurement basename: \(name)"
+        case .canonicalMissing(let url):
+            return "Canonical .ti3 not found: \(url.path)"
+        case .snapshotFailed(let reason):
+            return "Snapshot failed: \(reason)"
+        case .promoteFailed(let reason):
+            return "Promote failed: \(reason)"
+        case .noPassFiles:
+            return "No pass .ti3 snapshots are available."
+        }
+    }
+}
+
+/// Filesystem helpers for multi-pass measurement artefacts.
+///
+/// Pass snapshots use 1-based numbering and are tracked as
+/// `<basename>_passN.ti3`. Canonical `<basename>.ti3` only appears after
+/// Finish / Average (docs/24 #109, #110).
+public enum MeasurementArtefacts {
+
+    /// Find all existing pass snapshots in `cwd`, sorted numerically.
+    public static func passSnapshots(
+        basename: String,
+        cwd: URL,
+        fileManager: FileManager = .default
+    ) -> [URL] {
+        guard let entries = try? fileManager.contentsOfDirectory(
+            at: cwd,
+            includingPropertiesForKeys: nil,
+            options: [.skipsHiddenFiles]
+        ) else { return [] }
+
+        let prefix = "\(basename)_pass"
+        let suffix = "ti3"
+
+        let passes: [(Int, URL)] = entries.compactMap { url in
+            let name = url.lastPathComponent
+            guard url.pathExtension.lowercased() == suffix,
+                  name.hasPrefix(prefix)
+            else { return nil }
+
+            let numberPart = String(name.dropFirst(prefix.count).dropLast(4))
+            guard let number = Int(numberPart), number > 0 else { return nil }
+            return (number, url)
+        }
+
+        return passes
+            .sorted { $0.0 < $1.0 }
+            .map { $0.1 }
+    }
+
+    /// The next 1-based pass number.
+    public static func nextPassNumber(
+        basename: String,
+        cwd: URL,
+        fileManager: FileManager = .default
+    ) -> Int {
+        let existing = passSnapshots(basename: basename, cwd: cwd, fileManager: fileManager)
+        guard let last = existing.last else { return 1 }
+        let name = last.lastPathComponent
+        let prefix = "\(basename)_pass"
+        let numberPart = String(name.dropFirst(prefix.count).dropLast(4))
+        return (Int(numberPart) ?? 0) + 1
+    }
+
+    /// Snapshot canonical `<basename>.ti3` to `<basename>_passN.ti3` and remove canonical.
+    ///
+    /// The copy is written to a temp sibling and atomically renamed before canonical is deleted.
+    public static func snapshotPass(
+        basename: String,
+        cwd: URL,
+        fileManager: FileManager = .default
+    ) throws -> URL {
+        let cleanBasename = try PathSecurity.sanitizeBasename(basename)
+        let canonical = cwd.appendingPathComponent("\(cleanBasename).ti3")
+        guard fileManager.fileExists(atPath: canonical.path) else {
+            throw MeasurementArtefactError.canonicalMissing(canonical)
+        }
+
+        let passNumber = nextPassNumber(basename: cleanBasename, cwd: cwd, fileManager: fileManager)
+        let pass = cwd.appendingPathComponent("\(cleanBasename)_pass\(passNumber).ti3")
+        let temp = cwd.appendingPathComponent(".\(cleanBasename)_pass\(passNumber).ti3.iccery-snap.tmp")
+
+        if fileManager.fileExists(atPath: temp.path) {
+            try? fileManager.removeItem(at: temp)
+        }
+
+        do {
+            try fileManager.copyItem(at: canonical, to: temp)
+        } catch {
+            throw MeasurementArtefactError.snapshotFailed(error.localizedDescription)
+        }
+
+        if fileManager.fileExists(atPath: pass.path) {
+            try? fileManager.removeItem(at: pass)
+        }
+
+        do {
+            try fileManager.moveItem(at: temp, to: pass)
+        } catch {
+            try? fileManager.removeItem(at: temp)
+            throw MeasurementArtefactError.snapshotFailed(error.localizedDescription)
+        }
+
+        do {
+            try fileManager.removeItem(at: canonical)
+        } catch {
+            // The pass file is durable; canonical removal failure is logged but not fatal.
+            throw MeasurementArtefactError.snapshotFailed(error.localizedDescription)
+        }
+
+        return pass
+    }
+
+    /// Promote a single pass snapshot to canonical `<basename>.ti3`.
+    public static func promotePass(
+        pass: URL,
+        basename: String,
+        cwd: URL,
+        fileManager: FileManager = .default
+    ) throws -> URL {
+        let cleanBasename = try PathSecurity.sanitizeBasename(basename)
+        let canonical = cwd.appendingPathComponent("\(cleanBasename).ti3")
+        let temp = cwd.appendingPathComponent(".\(cleanBasename).ti3.iccery-promo.tmp")
+
+        guard fileManager.fileExists(atPath: pass.path) else {
+            throw MeasurementArtefactError.noPassFiles
+        }
+
+        if fileManager.fileExists(atPath: temp.path) {
+            try? fileManager.removeItem(at: temp)
+        }
+
+        do {
+            try fileManager.copyItem(at: pass, to: temp)
+        } catch {
+            throw MeasurementArtefactError.promoteFailed(error.localizedDescription)
+        }
+
+        if fileManager.fileExists(atPath: canonical.path) {
+            try? fileManager.removeItem(at: canonical)
+        }
+
+        do {
+            try fileManager.moveItem(at: temp, to: canonical)
+        } catch {
+            try? fileManager.removeItem(at: temp)
+            throw MeasurementArtefactError.promoteFailed(error.localizedDescription)
+        }
+
+        return canonical
+    }
+
+    /// Canonical `<basename>.ti3` URL, regardless of existence.
+    public static func canonicalURL(basename: String, cwd: URL) throws -> URL {
+        let cleanBasename = try PathSecurity.sanitizeBasename(basename)
+        return cwd.appendingPathComponent("\(cleanBasename).ti3")
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Process/ProcessLineDecoder.swift

@@ -35,6 +35,18 @@ public struct ProcessLineDecoder: Sendable {
         return rest.isEmpty ? nil : Self.decode(rest)
     }
 
+    /// Emits the current unterminated tail as a single line and clears it.
+    /// Used by `ProcessManager.flushPartialLine` for tools that emit
+    /// progress dots without newlines.
+    public mutating func flushPartial() -> String? {
+        guard !pending.isEmpty else { return nil }
+        var rest = pending
+        pending.removeAll(keepingCapacity: false)
+        if rest.last == 0x0D { rest = rest.dropLast() }
+        let text = Self.decode(rest)
+        return text.isEmpty ? nil : text
+    }
+
     private static func decode(_ bytes: Data.SubSequence) -> String {
         String(decoding: bytes, as: UTF8.self)
     }

Packages/ICCeryCore/Sources/ICCeryCore/Process/ProcessManager.swift

@@ -20,8 +20,11 @@ public struct CapturedResult: Sendable, Equatable {
 ///   with the prefix stripped; all other stdout is `stdout` events.
 /// - `exit` is emitted exactly once per child, and only after both
 ///   output pipes reach EOF — so no buffered output is lost on fast
-///   exits or kills.
-/// - `kill` drops the stdin handle so writers fail fast.
+///   exits or kills.  If EOFs never arrive, a watchdog finalizes.
+/// - `kill` runs a pre-kill hook (e.g. XY `q\n` + 500 ms park) before
+///   terminating.  Hooks are removed once the child finalizes.
+/// - `killAll` on `NSApplication.willTerminate` and last-window close
+///   runs all hooks and terminates every child (#147, #149).
 public actor ProcessManager {
 
     public static let rowColorsPrefix = "ROW_COLORS_JSON: "
@@ -92,12 +95,18 @@ public actor ProcessManager {
         /// pipes have also reached EOF.
         var pendingExitCode: Int32?
         var finalized = false
+        /// Watchdog that forces finalization if EOFs never arrive.
+        var finalizeTask: Task<Void, Never>?
     }
 
     private var children: [String: RunningChild] = [:]
     /// Processes owned by `runCaptured` (dup detection + kill support).
     private var captured: [String: Process] = [:]
 
+    /// Hooks run by `kill` before terminating the child.
+    /// Used by `chartread` to park an XY head with `q\n`.
+    private var preKillHooks: [String: @Sendable () async -> Void] = [:]
+
     /// Ids of currently-running children.
     public var runningIDs: [String] { Array(children.keys) + captured.keys }
 
@@ -105,6 +114,14 @@ public actor ProcessManager {
         children[id] != nil || captured[id] != nil
     }
 
+    // MARK: - Pre-kill hooks
+
+    /// Register a hook to run before `kill(id:)` terminates the child.
+    /// The hook is removed once the child finalizes.
+    public func setPreKillHook(id: String, hook: @escaping @Sendable () async -> Void) {
+        preKillHooks[id] = hook
+    }
+
     // MARK: - Spawn (streaming)
 
     /// Spawns a streaming child. Returns after spawn; callers wait for
@@ -142,14 +159,6 @@ public actor ProcessManager {
             stderrDecoder: ProcessLineDecoder()
         )
 
-        do {
-            try process.run()
-        } catch {
-            children.removeValue(forKey: id)
-            emit(.error(id: id, message: error.localizedDescription))
-            throw ProcessError.spawnFailed("\(binary.path): \(error.localizedDescription)")
-        }
-
         let stdoutHandle = stdoutPipe.fileHandleForReading
         let stderrHandle = stderrPipe.fileHandleForReading
         stdoutHandle.readabilityHandler = { [weak self] handle in
@@ -167,6 +176,15 @@ public actor ProcessManager {
             guard let self else { return }
             Task { await self.didTerminate(id: id, code: proc.terminationStatus) }
         }
+
+        do {
+            try process.run()
+        } catch {
+            preKillHooks.removeValue(forKey: id)
+            children.removeValue(forKey: id)
+            emit(.error(id: id, message: error.localizedDescription))
+            throw ProcessError.spawnFailed("\(binary.path): \(error.localizedDescription)")
+        }
     }
 
     // MARK: - Spawn (captured)
@@ -198,41 +216,114 @@ public actor ProcessManager {
             "spawn(captured) \(id): \(binary.path) \(LogSanitizer.sanitizeArgs(arguments))"
         )
 
-        // Register before run() so a concurrent duplicate spawn fails.
+        // Register and set up the termination hand-off before run() so
+        // a very fast exit is never missed (#50, #52).
         captured[id] = process
 
+        let capturedProcess = process
+
+        // Box is local and synchronised with an NSLock; the @unchecked
+        // Sendable annotation is safe because all access is under the lock.
+        final class Box: @unchecked Sendable {
+            private let lock = NSLock()
+            private var status: Int32?
+            private var continuation: CheckedContinuation<Int32, Never>?
+
+            /// Try to resume an already-stored continuation with the exit
+            /// status. Returns true if a continuation was resumed.
+            func resume(with status: Int32) -> Bool {
+                lock.lock()
+                if let cont = continuation {
+                    continuation = nil
+                    lock.unlock()
+                    cont.resume(returning: status)
+                    return true
+                }
+                self.status = status
+                lock.unlock()
+                return false
+            }
+
+            /// Store a continuation, returning any status that arrived
+            /// before it. The caller must resume with the returned status.
+            func store(_ continuation: CheckedContinuation<Int32, Never>) -> Int32? {
+                lock.lock()
+                if let status = status {
+                    self.status = nil
+                    self.continuation = nil
+                    lock.unlock()
+                    return status
+                }
+                self.continuation = continuation
+                // A fast exit may have raced past the first nil-check.
+                if let status = status {
+                    self.status = nil
+                    self.continuation = nil
+                    lock.unlock()
+                    return status
+                }
+                lock.unlock()
+                return nil
+            }
+        }
+        let box = Box()
+        capturedProcess.terminationHandler = { proc in
+            _ = box.resume(with: proc.terminationStatus)
+        }
+
         do {
             try process.run()
         } catch {
+            _ = box.resume(with: -1)
             captured.removeValue(forKey: id)
+            preKillHooks.removeValue(forKey: id)
             emit(.error(id: id, message: error.localizedDescription))
             throw ProcessError.spawnFailed("\(binary.path): \(error.localizedDescription)")
         }
 
-        async let outData = Task.detached {
-            stdoutPipe.fileHandleForReading.readDataToEndOfFile()
-        }.value
-        async let errData = Task.detached {
-            stderrPipe.fileHandleForReading.readDataToEndOfFile()
-        }.value
+        // Close the parent write ends so readDataToEndOfFile() gets EOF
+        // as soon as the child exits; the child still has its own copies.
+        try? stdoutPipe.fileHandleForWriting.close()
+        try? stderrPipe.fileHandleForWriting.close()
 
-        let code = await withCheckedContinuation { continuation in
-            process.terminationHandler = { proc in
-                continuation.resume(returning: proc.terminationStatus)
+        return await withTaskCancellationHandler {
+            async let outData = Task.detached {
+                stdoutPipe.fileHandleForReading.readDataToEndOfFile()
+            }.value
+            async let errData = Task.detached {
+                stderrPipe.fileHandleForReading.readDataToEndOfFile()
+            }.value
+
+            let code = await withCheckedContinuation { continuation in
+                if let status = box.store(continuation) {
+                    continuation.resume(returning: status)
+                }
+            }
+
+            let (out, err) = await (outData, errData)
+
+            // Emit the real exit code once, regardless of whether kill()
+            // already removed the id from `captured`.
+            _ = captured.removeValue(forKey: id)
+            preKillHooks.removeValue(forKey: id)
+            emit(.exit(id: id, code: code))
+
+            return CapturedResult(
+                stdout: String(decoding: out, as: UTF8.self),
+                stderr: String(decoding: err, as: UTF8.self),
+                exitCode: code
+            )
+        } onCancel: { [weak self] in
+            // If the awaiting Task is cancelled, terminate the child so
+            // callers like runApplycal never replace a good profile with
+            // a truncated tmp.
+            if capturedProcess.isRunning {
+                capturedProcess.terminate()
+            }
+            Task { [weak self] in
+                await self?.kill(id: id)
             }
         }
-
-        let (out, err) = await (outData, errData)
-        // If kill() already reaped this child, its exit event went out.
-        if captured.removeValue(forKey: id) != nil {
-            emit(.exit(id: id, code: code))
-        }
-
-        return CapturedResult(
-            stdout: String(decoding: out, as: UTF8.self),
-            stderr: String(decoding: err, as: UTF8.self),
-            exitCode: code
-        )
     }
 
     // MARK: - stdin
@@ -255,39 +346,89 @@ public actor ProcessManager {
         try sendStdin(id: id, bytes: Data(text.utf8))
     }
 
+    // MARK: - Partial-line flush
+
+    /// Emits the current unterminated tail of a streaming child's stdout
+    /// and stderr as ordinary lines.  Callers (e.g. `colprof`) use this
+    /// to flush progress dots without waiting for a newline.
+    public func flushPartialLine(id: String) {
+        guard var child = children[id], !child.finalized else { return }
+
+        if let tail = child.stdoutDecoder.flushPartial() {
+            if tail.hasPrefix(Self.rowColorsPrefix) {
+                let payload = Data(tail.dropFirst(Self.rowColorsPrefix.count).utf8)
+                emit(.jsonRow(id: id, payload: payload))
+            } else {
+                emit(.stdout(id: id, line: tail))
+            }
+        }
+        if let tail = child.stderrDecoder.flushPartial() {
+            emit(.stderr(id: id, line: tail))
+        }
+
+        children[id] = child
+    }
+
     // MARK: - Kill
 
-    /// Terminates a child. The `exit` event still fires exactly once.
-    /// stdin is dropped immediately so writers fail fast (docs/03 rule 7).
-    public func kill(id: String) {
+    /// Terminates a child.  First runs any registered pre-kill hook, then
+    /// drops stdin and signals the process.  For streaming children the
+    /// `exit` event is emitted once both stdout and stderr EOFs have been
+    /// seen (or the watchdog finalizes).  For captured children the real
+    /// exit code is emitted by `runCaptured` itself.
+    public func kill(id: String) async {
+        if let hook = preKillHooks.removeValue(forKey: id) {
+            await hook()
+        }
+
         if var child = children[id] {
             try? child.stdin?.close()
             child.stdin = nil
             children[id] = child
+
             if child.process.isRunning {
                 child.process.terminate()
-            } else {
-                Task { await self.didTerminate(id: id, code: child.process.terminationStatus) }
+            } else if child.pendingExitCode == nil {
+                // The process already exited but `didTerminate` has not
+                // run; synthesize it so `maybeFinalize` can fire.
+                didTerminate(id: id, code: child.process.terminationStatus)
             }
             return
         }
+
         if let process = captured[id] {
             if process.isRunning { process.terminate() }
-            if captured.removeValue(forKey: id) != nil {
-                emit(.exit(id: id, code: process.terminationStatus))
-            }
+            // Do not emit `.exit` here; `runCaptured` emits the real code
+            // after the process reaps.
+            return
         }
     }
 
     /// Terminates every running child; returns how many were signaled
     /// (`kill_all_processes`, docs/03). Mandatory on app exit (#147/#149).
     @discardableResult
-    public func killAll() -> Int {
-        let ids = Array(children.keys) + Array(captured.keys)
-        for id in ids { kill(id: id) }
+    public func killAll() async -> Int {
+        let ids = runningIDs
+        for id in ids { await kill(id: id) }
         return ids.count
     }
 
+    // MARK: - Force kill (SIGKILL fallback)
+
+    /// Sends `SIGKILL` to a streaming child if it is still running.
+    /// Used by the finalization watchdog when a graceful `terminate()`
+    /// does not cause the process to exit.
+    public func forceKill(id: String) {
+        guard let child = children[id],
+              !child.finalized,
+              child.process.isRunning
+        else { return }
+
+        let pid = child.process.processIdentifier
+        guard pid > 0 else { return }
+        _ = Darwin.kill(pid, SIGKILL)
+    }
+
     // MARK: - Internals
 
     private func childEnvironment(extra: [String: String]) -> [String: String] {
@@ -339,6 +480,16 @@ public actor ProcessManager {
         child.pendingExitCode = code
         try? child.stdin?.close()
         child.stdin = nil
+
+        // Start a watchdog in case the `readabilityHandler` EOFs never
+        // arrive after the process exits (e.g. a hung pipe).
+        child.finalizeTask = Task { [weak self] in
+            try? await Task.sleep(for: .seconds(2))
+            guard let self else { return }
+            await self.forceKill(id: id)
+            await self.forceFinalize(id: id)
+        }
+
         children[id] = child
         maybeFinalize(id: id)
     }
@@ -351,8 +502,12 @@ public actor ProcessManager {
               child.stdoutEOF, child.stderrEOF,
               !child.finalized
         else { return }
+
         child.finalized = true
+        child.finalizeTask?.cancel()
+        child.finalizeTask = nil
         children.removeValue(forKey: id)
+        preKillHooks.removeValue(forKey: id)
 
         // Flush unterminated tail lines.
         if var decoder = Optional(child.stdoutDecoder),
@@ -369,4 +524,20 @@ public actor ProcessManager {
         }
         emit(.exit(id: id, code: code))
     }
+
+    /// Forces finalization even when one or both EOFs are missing.
+    /// Used by the `didTerminate` watchdog.
+    private func forceFinalize(id: String) {
+        guard var child = children[id], !child.finalized else { return }
+
+        if child.pendingExitCode == nil {
+            child.pendingExitCode = -9
+        }
+        child.stdoutEOF = true
+        child.stderrEOF = true
+        child.finalizeTask?.cancel()
+        child.finalizeTask = nil
+        children[id] = child
+        maybeFinalize(id: id)
+    }
 }

Packages/ICCeryCore/Sources/ICCeryCore/Profile/ApplycalArgs.swift

@@ -0,0 +1,50 @@
+import Foundation
+
+/// Errors during `applycal` argv construction.
+public enum ApplycalArgError: LocalizedError, Equatable, Sendable {
+    case invalidCalibrationPath
+    case invalidInputProfileURL
+
+    public var errorDescription: String? {
+        switch self {
+        case .invalidCalibrationPath:
+            return "Calibration path is invalid or empty"
+        case .invalidInputProfileURL:
+            return "Input profile path is invalid or empty"
+        }
+    }
+}
+
+/// Pure argv builder for Argyll's `applycal` tool.
+///
+/// `applycal` is always run captured, never streamed.
+public enum ApplycalArgs {
+
+    /// Builds `applycal -v -a {cal} {input} [{output}]`.
+    ///
+    /// `-u` (unapply) is rejected at the builder level — the UI never
+    /// sends it (docs/04 §7.2).
+    public static func build(config: ApplycalConfig) throws -> [String] {
+        let cal = config.calibrationPath.trimmingCharacters(in: .whitespaces)
+        guard !cal.isEmpty else { throw ApplycalArgError.invalidCalibrationPath }
+
+        let input = config.inputProfileURL.path
+        guard !input.isEmpty else { throw ApplycalArgError.invalidInputProfileURL }
+
+        var args: [String] = ["-v"]
+        if config.unapply {
+            // Defensive: should never be called from the UI.
+            args.append("-u")
+        } else {
+            args.append("-a")
+        }
+
+        args.append(contentsOf: [cal, input])
+
+        if let output = config.outputProfileURL?.path, !output.isEmpty {
+            args.append(output)
+        }
+
+        return args
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/ApplycalConfig.swift

@@ -0,0 +1,22 @@
+import Foundation
+
+/// Configuration for an Argyll `applycal` run.
+public struct ApplycalConfig: Sendable, Equatable {
+    public var calibrationPath: String
+    public var inputProfileURL: URL
+    public var outputProfileURL: URL?
+    public var unapply: Bool
+
+    /// In-place when `outputProfileURL` is `nil`.
+    public init(
+        calibrationPath: String,
+        inputProfileURL: URL,
+        outputProfileURL: URL? = nil,
+        unapply: Bool = false
+    ) {
+        self.calibrationPath = calibrationPath
+        self.inputProfileURL = inputProfileURL
+        self.outputProfileURL = outputProfileURL
+        self.unapply = unapply
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/ColprofArgs.swift

@@ -0,0 +1,79 @@
+import Foundation
+
+/// Errors during `colprof` argv construction.
+public enum ColprofArgError: LocalizedError, Equatable, Sendable {
+    case invalidBasename(String)
+
+    public var errorDescription: String? {
+        switch self {
+        case .invalidBasename(let name):
+            return "Invalid colprof basename: \(name)"
+        }
+    }
+}
+
+/// Pure argv builder for Argyll's `colprof` tool.
+public enum ColprofArgs {
+
+    /// Builds `colprof` argv per the Gronod fork protocol.
+    ///
+    /// Always `-v -a {algorithm} -q {quality}`. Optional flags are added
+    /// only when their fields are non-empty and meaningful. `-f` has
+    /// special handling for "none" (omit), "" (bare flag), and a custom
+    /// `.sp` path (passed through). `-c`/`-d` viewing conditions are
+    /// skipped when set to "none".
+    public static func build(config: ColprofConfig) throws -> [String] {
+        let cleanBasename = try PathSecurity.sanitizeBasename(config.basename)
+
+        var args: [String] = ["-v"]
+
+        args.append(contentsOf: ["-a", config.algorithm])
+        args.append(contentsOf: ["-q", config.quality])
+
+        if let intent = config.intent?.trimmingCharacters(in: .whitespaces), !intent.isEmpty {
+            args.append(contentsOf: ["-t", intent])
+        }
+
+        if let fwa = config.fwa?.trimmingCharacters(in: .whitespaces) {
+            switch fwa.lowercased() {
+            case "none", "":
+                // "none" omits the flag; an explicit empty string means bare -f.
+                if fwa.isEmpty {
+                    args.append("-f")
+                }
+            default:
+                args.append(contentsOf: ["-f", fwa])
+            }
+        }
+
+        if let illuminant = config.illuminant?.trimmingCharacters(in: .whitespaces), !illuminant.isEmpty {
+            args.append(contentsOf: ["-i", illuminant])
+        }
+
+        if let observer = config.observer?.trimmingCharacters(in: .whitespaces), !observer.isEmpty {
+            args.append(contentsOf: ["-o", observer])
+        }
+
+        if let inputCond = config.inputViewingCond?.trimmingCharacters(in: .whitespaces),
+           !inputCond.isEmpty, inputCond.lowercased() != "none" {
+            args.append(contentsOf: ["-c", inputCond])
+        }
+
+        if let outputCond = config.outputViewingCond?.trimmingCharacters(in: .whitespaces),
+           !outputCond.isEmpty, outputCond.lowercased() != "none" {
+            args.append(contentsOf: ["-d", outputCond])
+        }
+
+        let profileDescription = config.description?.trimmingCharacters(in: .whitespaces)
+        if let description = profileDescription, !description.isEmpty {
+            args.append(contentsOf: ["-D", description])
+        }
+
+        if let copyright = config.copyright?.trimmingCharacters(in: .whitespaces), !copyright.isEmpty {
+            args.append(contentsOf: ["-C", copyright])
+        }
+
+        args.append(cleanBasename)
+        return args
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/ColprofConfig.swift

@@ -0,0 +1,45 @@
+import Foundation
+
+/// Configuration for an Argyll `colprof` run (issue #23, docs/16).
+public struct ColprofConfig: Sendable, Equatable {
+    public var algorithm: String
+    public var quality: String
+    public var intent: String?
+    public var fwa: String?
+    public var illuminant: String?
+    public var observer: String?
+    public var inputViewingCond: String?
+    public var outputViewingCond: String?
+    public var description: String?
+    public var copyright: String?
+    public var basename: String
+    public var workingDirectory: URL?
+
+    public init(
+        algorithm: String = "l",
+        quality: String = "m",
+        intent: String? = nil,
+        fwa: String? = nil,
+        illuminant: String? = nil,
+        observer: String? = nil,
+        inputViewingCond: String? = nil,
+        outputViewingCond: String? = nil,
+        description: String? = nil,
+        copyright: String? = nil,
+        basename: String,
+        workingDirectory: URL? = nil
+    ) {
+        self.algorithm = algorithm
+        self.quality = quality
+        self.intent = intent
+        self.fwa = fwa
+        self.illuminant = illuminant
+        self.observer = observer
+        self.inputViewingCond = inputViewingCond
+        self.outputViewingCond = outputViewingCond
+        self.description = description
+        self.copyright = copyright
+        self.basename = basename
+        self.workingDirectory = workingDirectory
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/ColprofProgress.swift

@@ -0,0 +1,30 @@
+import Foundation
+
+/// Classified `colprof` stdout progress milestone.
+public enum ColprofProgress: Sendable, Equatable {
+    case gamutMapping
+    case fittingClut
+    case writingIcc
+    case unknown
+}
+
+/// Parses `colprof` plaintext progress (docs/16 §6.3).
+///
+/// The Gronod fork supports `-u` JSON, but ICCery v2.0 does not pass it.
+/// Progress is therefore inferred from case-insensitive substring matches.
+public enum ColprofProgressClassifier {
+
+    public static func classify(line: String) -> ColprofProgress {
+        let lower = line.lowercased()
+        if lower.contains("gamut mapping") {
+            return .gamutMapping
+        }
+        if lower.contains("fitting") || lower.contains("clut") {
+            return .fittingClut
+        }
+        if lower.contains("writing") || lower.contains("icc profile") {
+            return .writingIcc
+        }
+        return .unknown
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/DriftAlert.swift

@@ -0,0 +1,49 @@
+import Foundation
+
+/// Computes a consecutive-breach warning from verification history.
+///
+/// A drift alert triggers when the most recent chronologically consecutive
+/// poor records form a run of at least two, and the first and last of that
+/// run are on distinct UTC days or at least one hour apart.
+public enum DriftAlert {
+
+    /// Returns an alert message, or `nil` when no consecutive breach exists.
+    public static func compute(from records: [VerificationRecord]) -> String? {
+        // Work in chronological order.
+        let chronological = records.sorted { $0.timestamp < $1.timestamp }
+
+        // Build the longest suffix of consecutive `.poor` records.
+        // Non-poor records break the run, so we stop at the first non-poor
+        // encountered from the end.
+        var run: [VerificationRecord] = []
+        for record in chronological.reversed() {
+            if record.status == .poor {
+                run.insert(record, at: 0)
+            } else {
+                break
+            }
+        }
+
+        guard run.count >= 2 else { return nil }
+
+        let first = run.first!
+        let last = run.last!
+
+        let sameDay = Calendar.utc.isDate(first.timestamp, inSameDayAs: last.timestamp)
+        let oneHour = last.timestamp.timeIntervalSince(first.timestamp) >= 3600
+
+        if !sameDay || oneHour {
+            return "Drift alert: poor results between \(first.id) and \(last.id)."
+        }
+
+        return nil
+    }
+}
+
+private extension Calendar {
+    static let utc: Calendar = {
+        var c = Calendar(identifier: .iso8601)
+        c.timeZone = TimeZone(identifier: "UTC")!
+        return c
+    }()
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/IccgamutArgs.swift

@@ -0,0 +1,29 @@
+import Foundation
+
+/// Errors during `iccgamut` argv construction.
+public enum IccgamutArgError: LocalizedError, Equatable, Sendable {
+    case invalidProfileURL
+
+    public var errorDescription: String? {
+        switch self {
+        case .invalidProfileURL:
+            return "iccgamut requires a valid profile path"
+        }
+    }
+}
+
+/// Pure argv builder for Argyll's `iccgamut` tool.
+public enum IccgamutArgs {
+
+    /// Builds `iccgamut -v -d {density} {profilePath}`.
+    ///
+    /// The caller is responsible for ensuring `density` is a positive
+    /// integer. `-d` here is surface **density**, not a directory.
+    public static func build(config: IccgamutConfig) throws -> [String] {
+        let path = config.profileURL.path
+        guard !path.isEmpty else { throw IccgamutArgError.invalidProfileURL }
+
+        let density = max(1, config.density)
+        return ["-v", "-d", "\(density)", path]
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/IccgamutConfig.swift

@@ -0,0 +1,12 @@
+import Foundation
+
+/// Configuration for an Argyll `iccgamut` run.
+public struct IccgamutConfig: Sendable, Equatable {
+    public var profileURL: URL
+    public var density: Int
+
+    public init(profileURL: URL, density: Int = 10) {
+        self.profileURL = profileURL
+        self.density = density
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/InstallProfileConfig.swift

@@ -0,0 +1,12 @@
+import Foundation
+
+/// Configuration for a profile installation.
+public struct InstallProfileConfig: Sendable, Equatable {
+    public var sourceURL: URL
+    public var options: InstallProfileOptions
+
+    public init(sourceURL: URL, options: InstallProfileOptions = InstallProfileOptions()) {
+        self.sourceURL = sourceURL
+        self.options = options
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/InstallProfileOptions.swift

@@ -0,0 +1,31 @@
+import Foundation
+
+/// Collision policy for profile installation.
+public enum ProfileCollisionPolicy: String, Sendable, Equatable, Codable, CaseIterable {
+    case overwrite
+    case rename
+    case cancel
+}
+
+/// Options for installing a finished profile into the OS colour store.
+public struct InstallProfileOptions: Sendable, Equatable, Codable {
+    public var forceOverwrite: Bool
+    public var preferSystem: Bool
+    public var collisionPolicy: ProfileCollisionPolicy
+    public var openColorPanel: Bool
+    public var calibrationNote: String?
+
+    public init(
+        forceOverwrite: Bool = false,
+        preferSystem: Bool = false,
+        collisionPolicy: ProfileCollisionPolicy = .cancel,
+        openColorPanel: Bool = false,
+        calibrationNote: String? = nil
+    ) {
+        self.forceOverwrite = forceOverwrite
+        self.preferSystem = preferSystem
+        self.collisionPolicy = collisionPolicy
+        self.openColorPanel = openColorPanel
+        self.calibrationNote = calibrationNote
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/InstallProfileResult.swift

@@ -0,0 +1,30 @@
+import Foundation
+
+/// Result of installing a profile into the OS colour store.
+public struct InstallProfileResult: Sendable, Equatable, Codable {
+    public var destPath: String
+    public var registered: Bool
+    public var overwritten: Bool
+    public var renamed: Bool
+    public var openedPanel: Bool
+    public var message: String
+    public var calibrationNote: String?
+
+    public init(
+        destPath: String,
+        registered: Bool,
+        overwritten: Bool,
+        renamed: Bool,
+        openedPanel: Bool,
+        message: String,
+        calibrationNote: String? = nil
+    ) {
+        self.destPath = destPath
+        self.registered = registered
+        self.overwritten = overwritten
+        self.renamed = renamed
+        self.openedPanel = openedPanel
+        self.message = message
+        self.calibrationNote = calibrationNote
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/ProfcheckArgs.swift

@@ -0,0 +1,37 @@
+import Foundation
+
+/// Errors during `profcheck` argv construction.
+public enum ProfcheckArgError: LocalizedError, Equatable, Sendable {
+    case missingTi3
+    case missingIcc
+    case invalidTi3Path
+
+    public var errorDescription: String? {
+        switch self {
+        case .missingTi3:
+            return "profcheck requires a .ti3 file"
+        case .missingIcc:
+            return "profcheck requires a profile (.icc/.icm)"
+        case .invalidTi3Path:
+            return "profcheck .ti3 path is invalid"
+        }
+    }
+}
+
+/// Pure argv builder for Argyll's `profcheck` tool.
+public enum ProfcheckArgs {
+
+    /// Builds `profcheck -v -k -s -u {ti3Path} {iccPath}`.
+    ///
+    /// The `-u` here is the Gronod fork JSON report flag, not the
+    /// generic `-u` auto-fix that some Argyll builds use.
+    public static func build(config: ProfcheckConfig) throws -> [String] {
+        let ti3Path = config.ti3URL.path
+        let iccPath = config.iccURL.path
+
+        guard !ti3Path.isEmpty else { throw ProfcheckArgError.missingTi3 }
+        guard !iccPath.isEmpty else { throw ProfcheckArgError.missingIcc }
+
+        return ["-v", "-k", "-s", "-u", ti3Path, iccPath]
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/ProfcheckConfig.swift

@@ -0,0 +1,12 @@
+import Foundation
+
+/// Configuration for an Argyll `profcheck` run.
+public struct ProfcheckConfig: Sendable, Equatable {
+    public var ti3URL: URL
+    public var iccURL: URL
+
+    public init(ti3URL: URL, iccURL: URL) {
+        self.ti3URL = ti3URL
+        self.iccURL = iccURL
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/ProfcheckParser.swift

@@ -0,0 +1,217 @@
+import Foundation
+
+/// Errors returned when `profcheck` output cannot be parsed.
+public enum ProfcheckParserError: LocalizedError, Equatable, Sendable {
+    case unparseable
+    case jsonDecodingFailed
+
+    public var errorDescription: String? {
+        switch self {
+        case .unparseable:
+            return "Could not parse profcheck report"
+        case .jsonDecodingFailed:
+            return "profcheck JSON report could not be decoded"
+        }
+    }
+}
+
+/// Parses the mixed JSON/text output from `profcheck -v -k -s -u`.
+public enum ProfcheckParser {
+
+    /// Parsing order (issue #25):
+    /// 1. Patch count from `No of test patches = N`.
+    /// 2. JSON objects; prefer one with `event == "report"` or `*_de2000` keys.
+    /// 3. Legacy text: `Profile check complete, errors(CIEDE2000): max. = X, avg. = Y, RMS = Z`.
+    /// 4. Broad regex fallback.
+    /// 5. If no metrics found, return a report whose `warning` is set.
+    public static func parse(_ output: String) -> ProfcheckReport {
+        var report = ProfcheckReport()
+
+        // 1. Patch count.
+        let patchRegex = try? NSRegularExpression(
+            pattern: #"No of test patches\s*=\s*(\d+)"#,
+            options: [.caseInsensitive]
+        )
+        if let match = patchRegex?.firstMatch(
+            in: output,
+            options: [],
+            range: NSRange(output.startIndex..., in: output)
+        ), let range = Range(match.range(at: 1), in: output) {
+            let count = Int(output[range])
+            report.patchCount = count
+        }
+
+        // 2. JSON objects.
+        let jsonObjects = extractJSONObjects(from: output)
+        for object in jsonObjects {
+            if let event = object["event"] as? String, event == "report" {
+                if let parsed = metrics(from: object) {
+                    apply(metrics: parsed, to: &report)
+                    return report
+                }
+            }
+            if hasMetricKeys(object) {
+                if let parsed = metrics(from: object) {
+                    apply(metrics: parsed, to: &report)
+                    return report
+                }
+            }
+        }
+
+        // 3. Legacy text.
+        let textRegex = try? NSRegularExpression(
+            pattern: #"Profile check complete, errors\(CIEDE2000\): max\.\s*=\s*([0-9.]+),\s*avg\.\s*=\s*([0-9.]+),\s*RMS\s*=\s*([0-9.]+)"#,
+            options: [.caseInsensitive]
+        )
+        if let match = textRegex?.firstMatch(
+            in: output,
+            options: [],
+            range: NSRange(output.startIndex..., in: output)
+        ) {
+            let numbers = (1...3).compactMap { i -> Double? in
+                guard let range = Range(match.range(at: i), in: output) else { return nil }
+                return Double(output[range])
+            }
+            if numbers.count == 3 {
+                report.maxDE = numbers[0]
+                report.avgDE = numbers[1]
+                report.rmsDE = numbers[2]
+                report.status = report.avgDE.map { VerificationStatus.from(avgDE: $0) }
+                return report
+            }
+        }
+
+        // 4. Broad regex fallback.
+        if let fallback = parseRegexFallback(output) {
+            var merged = fallback
+            merged.patchCount = report.patchCount
+            return merged
+        }
+
+        // 5. Unparseable.
+        report.warning = "profcheck output did not contain a recognisable report."
+        return report
+    }
+
+    // MARK: - JSON extraction
+
+    private static func extractJSONObjects(from output: String) -> [[String: Any]] {
+        var objects: [[String: Any]] = []
+        var start: String.Index?
+        var depth = 0
+
+        for index in output.indices {
+            let char = output[index]
+            if char == "{" {
+                if depth == 0 {
+                    start = index
+                }
+                depth += 1
+            } else if char == "}" {
+                if depth > 0 {
+                    depth -= 1
+                    if depth == 0, let start = start {
+                        let jsonString = String(output[start...index])
+                        if let data = jsonString.data(using: .utf8),
+                           let object = try? JSONSerialization.jsonObject(with: data) as? [String: Any] {
+                            objects.append(object)
+                        }
+                    }
+                }
+            }
+        }
+
+        return objects
+    }
+
+    private static func hasMetricKeys(_ object: [String: Any]) -> Bool {
+        let keys = [
+            "avg_de", "avg_de2000",
+            "peak_de", "peak_de2000", "max_de",
+            "rms", "rms_de"
+        ]
+        return keys.contains { object[$0] != nil }
+    }
+
+    private struct Metrics {
+        var avg: Double?
+        var max: Double?
+        var rms: Double?
+    }
+
+    private static func metrics(from object: [String: Any]) -> Metrics? {
+        var m = Metrics()
+        m.avg = doubleValue(for: "avg_de2000", in: object)
+            ?? doubleValue(for: "avg_de", in: object)
+        m.max = doubleValue(for: "peak_de2000", in: object)
+            ?? doubleValue(for: "peak_de", in: object)
+            ?? doubleValue(for: "max_de", in: object)
+            ?? doubleValue(for: "max_de2000", in: object)
+        m.rms = doubleValue(for: "rms", in: object)
+            ?? doubleValue(for: "rms_de", in: object)
+            ?? doubleValue(for: "rms_de2000", in: object)
+
+        guard m.avg != nil || m.max != nil || m.rms != nil else { return nil }
+        return m
+    }
+
+    private static func doubleValue(for key: String, in object: [String: Any]) -> Double? {
+        if let number = object[key] as? Double { return number }
+        if let number = object[key] as? NSNumber { return number.doubleValue }
+        if let string = object[key] as? String { return Double(string) }
+        return nil
+    }
+
+    private static func apply(metrics: Metrics, to report: inout ProfcheckReport) {
+        report.avgDE = metrics.avg
+        report.maxDE = metrics.max
+        report.rmsDE = metrics.rms
+        if let avg = metrics.avg {
+            report.status = VerificationStatus.from(avgDE: avg)
+        }
+    }
+
+    // MARK: - Regex fallback
+
+    private static func parseRegexFallback(_ output: String) -> ProfcheckReport? {
+        var report = ProfcheckReport()
+
+        let avgRegex = try? NSRegularExpression(
+            pattern: #"(?:avg\.?|average)\s*(?:=|:)\s*([0-9.]+)"#,
+            options: [.caseInsensitive]
+        )
+        let maxRegex = try? NSRegularExpression(
+            pattern: #"(?:max\.?|peak|maximum)\s*(?:=|:)\s*([0-9.]+)"#,
+            options: [.caseInsensitive]
+        )
+        let rmsRegex = try? NSRegularExpression(
+            pattern: #"(?:rms)\s*(?:=|:)\s*([0-9.]+)"#,
+            options: [.caseInsensitive]
+        )
+
+        report.avgDE = firstDouble(from: output, regex: avgRegex)
+        report.maxDE = firstDouble(from: output, regex: maxRegex)
+        report.rmsDE = firstDouble(from: output, regex: rmsRegex)
+
+        guard report.avgDE != nil || report.maxDE != nil || report.rmsDE != nil else {
+            return nil
+        }
+
+        if let avg = report.avgDE {
+            report.status = VerificationStatus.from(avgDE: avg)
+        }
+
+        return report
+    }
+
+    private static func firstDouble(from output: String, regex: NSRegularExpression?) -> Double? {
+        guard let regex = regex,
+              let match = regex.firstMatch(
+                in: output,
+                options: [],
+                range: NSRange(output.startIndex..., in: output)
+              ),
+              let range = Range(match.range(at: 1), in: output) else { return nil }
+        return Double(output[range])
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/ProfcheckReport.swift

@@ -0,0 +1,31 @@
+import Foundation
+
+/// Parsed result from a `profcheck -u` run.
+public struct ProfcheckReport: Sendable, Equatable, Codable {
+    public var patchCount: Int?
+    public var avgDE: Double?
+    public var maxDE: Double?
+    public var rmsDE: Double?
+    public var status: VerificationStatus?
+    public var warning: String?
+
+    public var isValid: Bool {
+        avgDE != nil && maxDE != nil && rmsDE != nil
+    }
+
+    public init(
+        patchCount: Int? = nil,
+        avgDE: Double? = nil,
+        maxDE: Double? = nil,
+        rmsDE: Double? = nil,
+        status: VerificationStatus? = nil,
+        warning: String? = nil
+    ) {
+        self.patchCount = patchCount
+        self.avgDE = avgDE
+        self.maxDE = maxDE
+        self.rmsDE = rmsDE
+        self.status = status
+        self.warning = warning
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/ProfileInstaller.swift

@@ -0,0 +1,238 @@
+import Foundation
+
+/// Errors thrown by `ProfileInstaller`.
+public enum ProfileInstallError: LocalizedError, Equatable, Sendable {
+    case unsafeStem(String)
+    case sourceMissing
+    case sourceNotProfile
+    case sourceTooSmall
+    case systemRequiresAdminRights
+    case copyFailed(String)
+    case cancelled
+
+    public var errorDescription: String? {
+        switch self {
+        case .unsafeStem(let stem):
+            return "Profile name contains unsafe characters: \(stem)"
+        case .sourceMissing:
+            return "Source profile does not exist"
+        case .sourceNotProfile:
+            return "Source must be a .icc or .icm file"
+        case .sourceTooSmall:
+            return "Source file is too small to be a valid profile"
+        case .systemRequiresAdminRights:
+            return "Installing to /Library/ColorSync/Profiles requires administrator rights"
+        case .copyFailed(let reason):
+            return "Could not install profile: \(reason)"
+        case .cancelled:
+            return "Install cancelled"
+        }
+    }
+}
+
+/// Installs an ICC/ICM profile into the OS colour store.
+public enum ProfileInstaller {
+
+    /// Resolves the destination URL that `install` would write to for the
+    /// given source and options, without copying anything. Useful for
+    /// collision previews in the UI.
+    public static func resolveDestinationURL(
+        for config: InstallProfileConfig,
+        fileManager: FileManager = .default
+    ) throws -> URL {
+        let sourceURL = config.sourceURL
+        let ext = sourceURL.pathExtension.lowercased()
+        guard ext == "icc" || ext == "icm" else {
+            throw ProfileInstallError.sourceNotProfile
+        }
+
+        try validateSourceURL(sourceURL)
+
+        let destDir = destinationDirectory(for: config.options, fileManager: fileManager)
+        return destDir.appendingPathComponent(sourceURL.lastPathComponent)
+    }
+
+    /// Installs `sourceURL` into `~/Library/ColorSync/Profiles` or
+    /// `/Library/ColorSync/Profiles`. Always copies, never moves.
+    public static func install(
+        config: InstallProfileConfig,
+        fileManager: FileManager = .default
+    ) throws -> InstallProfileResult {
+        let fm = fileManager
+
+        // Source validation.
+        let sourceURL = config.sourceURL
+        guard fm.fileExists(atPath: sourceURL.path) else {
+            throw ProfileInstallError.sourceMissing
+        }
+
+        let ext = sourceURL.pathExtension.lowercased()
+        guard ext == "icc" || ext == "icm" else {
+            throw ProfileInstallError.sourceNotProfile
+        }
+
+        let attrs = try? fm.attributesOfItem(atPath: sourceURL.path)
+        let size = attrs?[.size] as? UInt64 ?? 0
+        guard size >= 128 else {
+            throw ProfileInstallError.sourceTooSmall
+        }
+
+        try validateSourceURL(sourceURL)
+
+        // Destination directory.
+        let destURL = try resolveDestinationURL(for: config, fileManager: fm)
+        try? fm.createDirectory(
+            at: destURL.deletingLastPathComponent(),
+            withIntermediateDirectories: true
+        )
+
+        // Collision resolution.
+        let destExists = fm.fileExists(atPath: destURL.path)
+        if destExists {
+            if config.options.forceOverwrite {
+                return try performInstall(
+                    from: sourceURL,
+                    to: destURL,
+                    options: config.options,
+                    fileManager: fm,
+                    overwritten: true,
+                    renamed: false
+                )
+            } else if config.options.collisionPolicy == .rename {
+                let epoch = Int(Date().timeIntervalSince1970)
+                let stem = sourceURL.deletingPathExtension().lastPathComponent
+                let renamedURL = destURL.deletingLastPathComponent()
+                    .appendingPathComponent("\(stem)-\(epoch).\(ext)")
+                return try performInstall(
+                    from: sourceURL,
+                    to: renamedURL,
+                    options: config.options,
+                    fileManager: fm,
+                    overwritten: false,
+                    renamed: true
+                )
+            } else if config.options.collisionPolicy == .cancel {
+                throw ProfileInstallError.cancelled
+            } else {
+                // Default with askBeforeOverwrite — the app must decide.
+                throw ProfileInstallError.copyFailed("destination already exists")
+            }
+        }
+
+        return try performInstall(
+            from: sourceURL,
+            to: destURL,
+            options: config.options,
+            fileManager: fm,
+            overwritten: false,
+            renamed: false
+        )
+    }
+
+    // MARK: - Private helpers
+
+    private static func validateSourceURL(_ sourceURL: URL) throws {
+        let path = sourceURL.path
+        let stem = sourceURL.deletingPathExtension().lastPathComponent
+
+        // Reject backslashes anywhere in the path.
+        guard !path.contains("\\") else {
+            throw ProfileInstallError.unsafeStem(stem)
+        }
+
+        // Reject any path component that is literally "." or "..".
+        // This allows names like "foo..bar" while blocking real traversal.
+        for component in sourceURL.pathComponents {
+            if component == "." || component == ".." {
+                throw ProfileInstallError.unsafeStem(stem)
+            }
+        }
+    }
+
+    private static func destinationDirectory(
+        for options: InstallProfileOptions,
+        fileManager: FileManager
+    ) -> URL {
+        if options.preferSystem {
+            return URL(fileURLWithPath: "/Library/ColorSync/Profiles")
+        } else {
+            return fileManager.homeDirectoryForCurrentUser
+                .appendingPathComponent("Library/ColorSync/Profiles")
+        }
+    }
+
+    private static func performInstall(
+        from sourceURL: URL,
+        to destURL: URL,
+        options: InstallProfileOptions,
+        fileManager: FileManager,
+        overwritten: Bool,
+        renamed: Bool
+    ) throws -> InstallProfileResult {
+        let fm = fileManager
+        let tmpURL = destURL.appendingPathExtension("iccery-install.tmp")
+
+        // Remove stale tmp.
+        try? fm.removeItem(at: tmpURL)
+
+        do {
+            try fm.copyItem(at: sourceURL, to: tmpURL)
+
+            let attrs = try? fm.attributesOfItem(atPath: tmpURL.path)
+            let tmpSize = attrs?[.size] as? UInt64 ?? 0
+            guard tmpSize >= 128 else {
+                try? fm.removeItem(at: tmpURL)
+                throw ProfileInstallError.sourceTooSmall
+            }
+
+            if fm.fileExists(atPath: destURL.path) {
+                _ = try fm.replaceItemAt(destURL, withItemAt: tmpURL)
+            } else {
+                try fm.moveItem(at: tmpURL, to: destURL)
+            }
+        } catch {
+            try? fm.removeItem(at: tmpURL)
+
+            // Surface a clear admin-rights hint when writing to system.
+            if destURL.path.hasPrefix("/Library/") && !fm.fileExists(atPath: destURL.path) {
+                throw ProfileInstallError.systemRequiresAdminRights
+            }
+
+            if let installError = error as? ProfileInstallError {
+                throw installError
+            }
+            throw ProfileInstallError.copyFailed(error.localizedDescription)
+        }
+
+        let registered = fm.fileExists(atPath: destURL.path)
+
+        var openedPanel = false
+        if options.openColorPanel {
+            openedPanel = openColorSyncUtility()
+        }
+
+        return InstallProfileResult(
+            destPath: destURL.path,
+            registered: registered,
+            overwritten: overwritten,
+            renamed: renamed,
+            openedPanel: openedPanel,
+            message: "Profile installed to \(destURL.path)",
+            calibrationNote: options.calibrationNote
+        )
+    }
+
+    private static func openColorSyncUtility() -> Bool {
+        let task = Process()
+        task.launchPath = "/usr/bin/open"
+        task.arguments = ["-a", "ColorSync Utility"]
+        task.environment = ["ARGYLL_NOT_INTERACTIVE": "1"]
+        do {
+            try task.run()
+            task.waitUntilExit()
+        } catch {
+            return false
+        }
+        return true
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/VerificationHistoryStore.swift

@@ -0,0 +1,122 @@
+import Foundation
+
+/// Persistence for `VerificationRecord` entries.
+public actor VerificationHistoryStore {
+
+    /// Default cap.
+    public static let defaultCapacity = 1000
+
+    /// Path to the JSON store.
+    public let url: URL
+
+    /// In-memory cache, kept in sync with disk.
+    private var records: [VerificationRecord] = []
+
+    private let capacity: Int
+    private let encoder: JSONEncoder
+    private let decoder: JSONDecoder
+
+    public init(
+        url: URL = AppPaths.appDataDir.appendingPathComponent("verification_history.json"),
+        capacity: Int = defaultCapacity
+    ) {
+        self.url = url
+        self.capacity = capacity
+
+        self.encoder = JSONEncoder()
+        self.encoder.dateEncodingStrategy = .iso8601
+        self.encoder.outputFormatting = [.prettyPrinted, .sortedKeys]
+
+        self.decoder = JSONDecoder()
+        self.decoder.dateDecodingStrategy = .iso8601
+    }
+
+    /// Loads records from disk. Returns the existing cache if already loaded.
+    ///
+    /// Throws when the file exists but cannot be parsed; the existing file
+    /// is never overwritten in that case.
+    public func load() throws -> [VerificationRecord] {
+        guard records.isEmpty else { return records }
+        let fm = FileManager.default
+        guard fm.fileExists(atPath: url.path),
+              let data = try? Data(contentsOf: url) else { return [] }
+        records = try decoder.decode([VerificationRecord].self, from: data)
+        return records
+    }
+
+    /// Returns all records.
+    public func all() -> [VerificationRecord] {
+        records
+    }
+
+    /// Records matching the optional printer filter.
+    public func filtered(by printer: String?) -> [VerificationRecord] {
+        guard let printer = printer, !printer.isEmpty else { return records }
+        return records.filter { $0.printerName == printer }
+    }
+
+    /// Appends a record, trims to capacity, and writes atomically.
+    ///
+    /// Loads the existing history first and propagates any load error so an
+    /// unparseable file is never overwritten.
+    @discardableResult
+    public func append(_ record: VerificationRecord) throws -> [VerificationRecord] {
+        try load()
+
+        var updated = records
+        updated.append(record)
+        if updated.count > capacity {
+            updated.sort { $0.timestamp < $1.timestamp }
+            updated = Array(updated.suffix(capacity))
+        }
+
+        try write(updated)
+        records = updated
+        return updated
+    }
+
+    /// Removes all history and updates disk.
+    public func clear() throws {
+        try write([])
+        records = []
+    }
+
+    /// RFC-4180 CSV export.
+    public func exportCSV() -> String {
+        var lines: [String] = [
+            csvRow(["id", "profile_name", "printer_name", "avg_de", "max_de", "rms_de", "patch_count", "status", "timestamp"])
+        ]
+
+        for record in records {
+            lines.append(csvRow([
+                record.id,
+                record.profileName,
+                record.printerName,
+                String(record.avgDE),
+                String(record.maxDE),
+                String(record.rmsDE),
+                String(record.patchCount),
+                record.status.rawValue,
+                ISO8601DateFormatter().string(from: record.timestamp)
+            ]))
+        }
+
+        return lines.joined(separator: "\n") + "\n"
+    }
+
+    /// Writes `records` through a temp file and rename.
+    private func write(_ records: [VerificationRecord]) throws {
+        let data = try encoder.encode(records)
+        try AtomicFileWriter.write(data, to: url)
+    }
+
+    private func csvRow(_ fields: [String]) -> String {
+        fields.map { field in
+            let escaped = field.replacingOccurrences(of: "\"", with: "\"\"")
+            if field.contains(",") || field.contains("\"") || field.contains("\n") || field.contains("\r") {
+                return "\"\(escaped)\""
+            }
+            return escaped
+        }.joined(separator: ",")
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/VerificationRecord.swift

@@ -0,0 +1,36 @@
+import Foundation
+
+/// A single entry in the verification history store.
+public struct VerificationRecord: Sendable, Equatable, Codable, Identifiable {
+    public var id: String
+    public var profileName: String
+    public var printerName: String
+    public var avgDE: Double
+    public var maxDE: Double
+    public var rmsDE: Double
+    public var patchCount: Int
+    public var status: VerificationStatus
+    public var timestamp: Date
+
+    public init(
+        id: String,
+        profileName: String,
+        printerName: String,
+        avgDE: Double,
+        maxDE: Double,
+        rmsDE: Double,
+        patchCount: Int,
+        status: VerificationStatus,
+        timestamp: Date
+    ) {
+        self.id = id
+        self.profileName = profileName
+        self.printerName = printerName
+        self.avgDE = avgDE
+        self.maxDE = maxDE
+        self.rmsDE = rmsDE
+        self.patchCount = patchCount
+        self.status = status
+        self.timestamp = timestamp
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Profile/VerificationStatus.swift

@@ -0,0 +1,32 @@
+import Foundation
+
+/// ICCery quality band for a verification run.
+///
+/// Bands are on the **average** ΔE₀₀:
+/// - < 1.0 → Excellent
+/// - < 2.0 → Good
+/// - < 3.5 → Acceptable
+/// - ≥ 3.5 → Warning
+public enum VerificationStatus: String, Sendable, Equatable, Codable, CaseIterable {
+    case excellent
+    case good
+    case acceptable
+    case poor
+
+    public var displayName: String {
+        switch self {
+        case .excellent: return "Excellent"
+        case .good: return "Good"
+        case .acceptable: return "Acceptable"
+        case .poor: return "Warning"
+        }
+    }
+
+    /// Returns the quality band for the given average ΔE₀₀.
+    public static func from(avgDE: Double) -> VerificationStatus {
+        if avgDE < 1.0 { return .excellent }
+        if avgDE < 2.0 { return .good }
+        if avgDE < 3.5 { return .acceptable }
+        return .poor
+    }
+}

Resources/Argyll/mocks/chartread.mock

@@ -1,75 +1,79 @@
 #!/bin/bash
-# Mock script for chartread -u
-# This script simulates the behaviour of chartread for testing purposes.
+# Mock chartread for bundled/manual testing.
+# Supports handheld and XY modes. Writes basename.ti3 on 'd'.
+MODE="${MOCK_CHARTREAD_MODE:-strip}"
+BASENAME=""
 
-# Check for --xy argument or MOCK_XY_TABLE environment variable
-IS_XY=0
+# Basename is the last non-flag argument.
 for arg in "$@"; do
-    if [ "$arg" = "--xy" ]; then
-        IS_XY=1
-        break
-    fi
+  case "$arg" in
+    -*) ;;
+    *) BASENAME="$arg" ;;
+  esac
 done
 
-if [ "$IS_XY" = "1" ] || [ "${MOCK_XY_TABLE}" = "1" ]; then
-    echo "Place instrument on calibration tile and hit [Space] to calibrate."
-    read -r _calib
-    echo "Calibration successful."
+read_input() {
+  IFS= read -r line || return 1
+}
 
-    echo "Please place sheet 1 of 1 on the table"
-    echo "hit return to continue, Esc or 'q' to give up"
-    read -r _sheet1
+emit_row() {
+  printf 'ROW_COLORS_JSON: %s\n' "$1"
+}
 
-    echo "locate patch A1 with the sight,"
-    echo "then hit return to continue"
-    read -r _fid1
+write_ti3() {
+  if [ -n "$BASENAME" ]; then
+    echo "MOCK_TI3" > "${BASENAME}.ti3"
+  fi
+}
 
-    echo "locate patch B24 with the sight,"
-    echo "then hit return to continue"
-    read -r _fid2
+if [ "$MODE" = "xy" ]; then
+  echo "Place instrument on calibration tile and hit [Space] to calibrate."
+  read_input
+  echo "Calibration successful."
 
-    echo "Reading sheet 1..."
-    sleep 0.5
+  echo "Please place sheet 1 of 1 on the table"
+  echo "hit return to continue, Esc or 'q' to give up"
+  read_input
 
-    # Emit mock JSON for strip A
-    cat << 'EOF'
-ROW_COLORS_JSON: {"event": "row_complete", "row_id": "A", "row_index": 0, "total_rows": 2, "patch_count": 3, "patches": [{"id": "1", "loc": "A1", "is_pad": false, "device": [0.0, 50.0, 100.0], "expected": {"XYZ": [18.4210, 20.1234, 15.6789], "Lab": [51.98, -8.45, 12.32]}, "measured": {"XYZ": [18.5120, 20.0451, 15.7100], "Lab": [51.89, -8.31, 12.15]}}, {"id": "2", "loc": "A2", "is_pad": false, "device": [10.0, 60.0, 90.0], "expcted": {"Lab": [60.0, 10.0, -20.0]}, "measured": {"Lab": [60.1, 10.5, -19.5]}}, {"id": "3", "loc": "A3", "is_pad": true, "device": [100.0, 100.0, 100.0]}]}
-EOF
+  echo "locate patch A1 with the sight,"
+  echo "then hit return to continue"
+  read_input
 
-    # Emit mock JSON for strip B
-    cat << 'EOF'
-ROW_COLORS_JSON: {"event": "row_complete", "row_id": "B", "row_index": 1, "total_rows": 2, "patch_count": 2, "patches": [{"id": "4", "loc": "B1", "is_pad": false, "device": [100.0, 0.0, 0.0], "expected": {"Lab": [40.0, 40.0, 40.0]}, "measured": {"Lab": [38.0, 41.0, 39.0]}}, {"id": "5", "loc": "B2", "is_pad": false, "device": [0.0, 100.0, 0.0], "expcted": {"Lab": [80.0, -50.0, 50.0]}, "measured": {"Lab": [79.0, -49.0, 51.0]}}]}
-EOF
+  echo "Reading sheet 1..."
+  emit_row '{"event": "row_complete", "row_id": "A", "row_index": 0, "total_rows": 1, "patch_count": 3, "patches": [{"id": "1", "loc": "A1", "is_pad": false, "device": [0.0, 50.0, 100.0], "expected": {"XYZ": [18.4210, 20.1234, 15.6789], "Lab": [51.98, -8.45, 12.32]}, "measured": {"XYZ": [18.5120, 20.0451, 15.7100], "Lab": [51.89, -8.31, 12.15]}}, {"id": "2", "loc": "A2", "is_pad": false, "device": [10.0, 60.0, 90.0], "expected": {"Lab": [60.0, 10.0, -20.0]}, "measured": {"Lab": [60.1, 10.5, -19.5]}}, {"id": "3", "loc": "A3", "is_pad": true, "device": [100.0, 100.0, 100.0], "measured": {"Lab": [95.0, 0.0, 0.0]}}]}'
 
-    echo "Sheet 1 of 1 read OK"
-    echo "Please remove last sheet from table"
-    exit 0
+  echo "Sheet 1 of 1 read OK"
+  echo "Please remove last sheet from table"
+  echo "'d' if/when done"
+  while read_input; do
+    case "$line" in
+      d*) write_ti3; exit 0 ;;
+      q*) exit 0 ;;
+    esac
+  done
+  exit 0
 fi
 
-# Handheld / strip reader simulation
+# Handheld / strip mode (default)
 echo "Place instrument on calibration tile and hit [Space] to calibrate."
-
-# We don't really wait for input, just wait 1 second
-sleep 1
+read_input
 echo "Calibration successful."
-echo "Hit [Space] to read strip A (or 's' to skip)."
 
-sleep 1
+echo "Hit [Space] to read strip A"
+read_input
 echo "Reading strip A..."
+emit_row '{"event": "row_complete", "row_id": "A", "row_index": 0, "total_rows": 2, "patch_count": 3, "patches": [{"id": "1", "loc": "A1", "is_pad": false, "device": [0.0, 50.0, 100.0], "expected": {"XYZ": [18.4210, 20.1234, 15.6789], "Lab": [51.98, -8.45, 12.32]}, "measured": {"XYZ": [18.5120, 20.0451, 15.7100], "Lab": [51.89, -8.31, 12.15]}}, {"id": "2", "loc": "A2", "is_pad": false, "device": [10.0, 60.0, 90.0], "expected": {"Lab": [60.0, 10.0, -20.0]}, "measured": {"Lab": [60.1, 10.5, -19.5]}}, {"id": "3", "loc": "A3", "is_pad": true, "device": [100.0, 100.0, 100.0], "measured": {"Lab": [95.0, 0.0, 0.0]}}]}'
 
-# Emit mock JSON for strip A
-cat << 'EOF'
-ROW_COLORS_JSON: {"event": "row_complete", "row_id": "A", "row_index": 0, "total_rows": 2, "patch_count": 3, "patches": [{"id": "1", "loc": "A1", "is_pad": false, "device": [0.0, 50.0, 100.0], "expected": {"XYZ": [18.4210, 20.1234, 15.6789], "Lab": [51.98, -8.45, 12.32]}, "measured": {"XYZ": [18.5120, 20.0451, 15.7100], "Lab": [51.89, -8.31, 12.15]}}, {"id": "2", "loc": "A2", "is_pad": false, "device": [10.0, 60.0, 90.0], "expcted": {"Lab": [60.0, 10.0, -20.0]}, "measured": {"Lab": [60.1, 10.5, -19.5]}}, {"id": "3", "loc": "A3", "is_pad": true, "device": [100.0, 100.0, 100.0]}]}
-EOF
-
-echo "Hit [Space] to read strip B (or 's' to skip)."
-sleep 1
+echo "Hit [Space] to read strip B"
+read_input
 echo "Reading strip B..."
+emit_row '{"event": "row_complete", "row_id": "B", "row_index": 1, "total_rows": 2, "patch_count": 2, "patches": [{"id": "4", "loc": "B1", "is_pad": false, "device": [100.0, 0.0, 0.0], "expected": {"Lab": [40.0, 40.0, 40.0]}, "measured": {"Lab": [38.0, 41.0, 39.0]}}, {"id": "5", "loc": "B2", "is_pad": false, "device": [0.0, 100.0, 0.0], "expected": {"Lab": [80.0, -50.0, 50.0]}, "measured": {"Lab": [79.0, -49.0, 51.0]}}]}'
 
-# Emit mock JSON for strip B
-cat << 'EOF'
-ROW_COLORS_JSON: {"event": "row_complete", "row_id": "B", "row_index": 1, "total_rows": 2, "patch_count": 2, "patches": [{"id": "4", "loc": "B1", "is_pad": false, "device": [100.0, 0.0, 0.0], "expected": {"Lab": [40.0, 40.0, 40.0]}, "measured": {"Lab": [38.0, 41.0, 39.0]}}, {"id": "5", "loc": "B2", "is_pad": false, "device": [0.0, 100.0, 0.0], "expected": {"Lab": [80.0, -50.0, 50.0]}, "measured": {"Lab": [79.0, -49.0, 51.0]}}]}
-EOF
-
-echo "Ready to read... done."
+echo "'d' if/when done"
+while read_input; do
+  case "$line" in
+    d*) write_ti3; exit 0 ;;
+    q*) exit 0 ;;
+  esac
+done
 exit 0

Sources/ICCery/AboutView.swift

@@ -0,0 +1,62 @@
+import SwiftUI
+import ICCeryCore
+
+/// About dialog for ICCery (issue #31, docs/21 §Modals).
+struct AboutView: View {
+    let onClose: () -> Void
+
+    private let info = ArtefactFiles.appInfo()
+
+    var body: some View {
+        VStack(spacing: 20) {
+            Image("ICCery-logo")
+                .resizable()
+                .scaledToFit()
+                .frame(height: 64)
+
+            Text("ICCery")
+                .font(.title)
+                .foregroundStyle(Theme.text)
+
+            VStack(alignment: .leading, spacing: 4) {
+                HStack {
+                    Text("Version:")
+                        .foregroundStyle(.secondary)
+                    Text(info.version)
+                        .foregroundStyle(Theme.text)
+                        .accessibilityIdentifier("aboutVersion")
+                }
+                HStack {
+                    Text("Build:")
+                        .foregroundStyle(.secondary)
+                    Text(info.build)
+                        .foregroundStyle(Theme.text)
+                }
+                HStack {
+                    Text("Build date:")
+                        .foregroundStyle(.secondary)
+                    Text(info.buildDate)
+                        .foregroundStyle(Theme.text)
+                        .accessibilityIdentifier("aboutBuildDate")
+                }
+            }
+            .font(.callout)
+
+            Text("Native macOS printer profiling workstation.")
+                .font(.caption)
+                .foregroundStyle(.secondary)
+                .multilineTextAlignment(.center)
+
+            Button("Close") {
+                onClose()
+            }
+            .controlSize(.large)
+            .keyboardShortcut(.cancelAction)
+            .accessibilityIdentifier("closeAboutBtn")
+        }
+        .padding(32)
+        .frame(width: 360)
+        .background(Theme.panel)
+        .accessibilityIdentifier("aboutDialog")
+    }
+}

Sources/ICCery/AppEnvironment.swift

@@ -12,6 +12,7 @@ struct AppEnvironment: Sendable {
     let presetStore: PresetStore
     let runner: ArgyllRunner
     let cupsService: CupsService
+    let historyStore: VerificationHistoryStore
 
     static func live(
         environment: [String: String] = ProcessInfo.processInfo.environment
@@ -38,7 +39,8 @@ struct AppEnvironment: Sendable {
             ),
             cupsService: CupsService(
                 processManager: .shared,
-                binaryDir: cupsDir)
+                binaryDir: cupsDir),
+            historyStore: VerificationHistoryStore()
         )
     }
 }
@@ -66,6 +68,8 @@ enum UITestHooks {
     static var existingTargetURL: URL? { url("ICCERY_TEST_EXISTING_TARGET") }
     /// `select_directory` result (working-directory browse).
     static var workDirURL: URL? { url("ICCERY_TEST_WORKDIR") }
+    /// Dataset import file (`.ti3`, `.txt`, `.cgats`, `.csv`).
+    static var datasetImportURL: URL? { url("ICCERY_TEST_DATASET_IMPORT") }
     /// Preset import file.
     static var presetImportURL: URL? { url("ICCERY_TEST_PRESET_IMPORT") }
     /// Preset export destination.

Sources/ICCery/DriftChartView.swift

@@ -0,0 +1,121 @@
+import SwiftUI
+import ICCeryCore
+
+/// Minimal line chart for drift history without depending on the
+/// `Charts` framework link. Renders avg/max series with shaded quality
+/// bands.
+struct DriftChartView: View {
+    let records: [VerificationRecord]
+
+    var body: some View {
+        GeometryReader { geometry in
+            let width = geometry.size.width
+            let height = geometry.size.height
+
+            ZStack(alignment: .topLeading) {
+                if let (_, _, _, maxV) = scales(in: height) {
+                    // Quality bands — bottom (red, > 3.5) drawn first, then
+                    // orange, yellow, green so the upper-most bands overlay.
+                    band(from: 3.5, to: maxV, color: .red.opacity(0.12), height: height, maxValue: maxV)
+                    band(from: 2.0, to: 3.5, color: .orange.opacity(0.12), height: height, maxValue: maxV)
+                    band(from: 1.0, to: 2.0, color: .yellow.opacity(0.12), height: height, maxValue: maxV)
+                    band(from: 0.0, to: 1.0, color: .green.opacity(0.12), height: height, maxValue: maxV)
+                }
+
+                if !records.isEmpty, let (minT, maxT, minV, maxV) = scales(in: height) {
+                    // Average ΔE series
+                    Path { path in
+                        for (index, record) in records.enumerated() {
+                            let pt = point(
+                                for: record,
+                                minTime: minT,
+                                maxTime: maxT,
+                                minValue: minV,
+                                maxValue: maxV,
+                                width: width,
+                                height: height,
+                                keyPath: \.avgDE
+                            )
+                            if index == 0 {
+                                path.move(to: pt)
+                            } else {
+                                path.addLine(to: pt)
+                            }
+                        }
+                    }
+                    .stroke(Color.blue, lineWidth: 2)
+                    .accessibilityIdentifier("driftAvgSeries")
+
+                    // Max ΔE series
+                    Path { path in
+                        for (index, record) in records.enumerated() {
+                            let pt = point(
+                                for: record,
+                                minTime: minT,
+                                maxTime: maxT,
+                                minValue: minV,
+                                maxValue: maxV,
+                                width: width,
+                                height: height,
+                                keyPath: \.maxDE
+                            )
+                            if index == 0 {
+                                path.move(to: pt)
+                            } else {
+                                path.addLine(to: pt)
+                            }
+                        }
+                    }
+                    .stroke(Color.orange, lineWidth: 2)
+                    .accessibilityIdentifier("driftMaxSeries")
+                } else {
+                    Text("No data")
+                        .font(.caption)
+                        .foregroundStyle(.secondary)
+                        .frame(maxWidth: .infinity, maxHeight: .infinity)
+                }
+            }
+        }
+    }
+
+    private func band(
+        from lower: Double,
+        to upper: Double,
+        color: Color,
+        height: CGFloat,
+        maxValue: Double
+    ) -> some View {
+        let yTop = valueY(lower, minValue: 0, maxValue: maxValue, height: height)
+        let yBottom = valueY(upper, minValue: 0, maxValue: maxValue, height: height)
+        return color
+            .frame(height: yBottom - yTop)
+            .offset(y: yTop)
+    }
+
+    private func scales(in height: CGFloat) -> (Date, Date, Double, Double)? {
+        guard let minT = records.first?.timestamp, let maxT = records.last?.timestamp else { return nil }
+        let maxV = max(records.map { max($0.avgDE, $0.maxDE) }.max() ?? 5.0, 5.0)
+        return (minT, maxT, 0.0, maxV)
+    }
+
+    private func point(
+        for record: VerificationRecord,
+        minTime: Date,
+        maxTime: Date,
+        minValue: Double,
+        maxValue: Double,
+        width: CGFloat,
+        height: CGFloat,
+        keyPath: KeyPath<VerificationRecord, Double>
+    ) -> CGPoint {
+        let timeSpan = max(1, maxTime.timeIntervalSince(minTime))
+        let x = width * CGFloat(record.timestamp.timeIntervalSince(minTime) / timeSpan)
+        let y = valueY(record[keyPath: keyPath], minValue: minValue, maxValue: maxValue, height: height)
+        return CGPoint(x: x, y: y)
+    }
+
+    private func valueY(_ value: Double, minValue: Double, maxValue: Double, height: CGFloat) -> CGFloat {
+        let valueSpan = max(1, maxValue - minValue)
+        return height - height * CGFloat((value - minValue) / valueSpan)
+    }
+}

Sources/ICCery/HelpOverlayView.swift

@@ -0,0 +1,31 @@
+import SwiftUI
+
+/// Reusable help overlay badge that does not reflow layout (#171).
+///
+/// When `showing` is `true`, a small indicator is rendered as an overlay at the
+/// top-trailing corner of the wrapped view. The native `.help` tooltip is always
+/// available on hover, so the overlay is purely a visual cue in help mode.
+struct HelpOverlay: ViewModifier {
+    let text: String
+    @Binding var showing: Bool
+
+    func body(content: Content) -> some View {
+        content
+            .help(text)
+            .overlay(alignment: .topTrailing) {
+                if showing {
+                    Image(systemName: "questionmark.circle.fill")
+                        .font(.system(size: 10, weight: .bold))
+                        .foregroundStyle(Theme.accent)
+                        .offset(x: 8, y: -8)
+                }
+            }
+    }
+}
+
+extension View {
+    /// Adds a non-reflowing help overlay to the view.
+    func helpOverlay(_ text: String, showing: Binding<Bool>) -> some View {
+        modifier(HelpOverlay(text: text, showing: showing))
+    }
+}

Sources/ICCery/MeasurementWorkflowViewModel.swift

@@ -0,0 +1,462 @@
+import Foundation
+import Observation
+import SwiftUI
+import ICCeryCore
+
+/// A single evaluated swatch for the live grid.
+struct Swatch: Sendable, Equatable, Identifiable {
+    let rowId: String
+    let loc: String
+    let isPad: Bool
+    let intended: DisplayRGB
+    let measured: DisplayRGB
+    let deltaE: Double?
+    let classification: SwatchClassification
+
+    var id: String { "\(rowId)\(loc)" }
+}
+
+/// A row of swatches in display order.
+struct SwatchRow: Sendable, Equatable, Identifiable {
+    let index: Int
+    let rowId: String
+    let patches: [Swatch]
+
+    var id: String { rowId }
+}
+
+/// Stage of the XY-table badge bar.
+enum XYStep: Equatable, Sendable {
+    case place, align, scan, remove
+}
+
+/// Stage 3 workflow state and interaction (issues #18–#22).
+@MainActor
+@Observable
+final class MeasurementWorkflowViewModel {
+
+    // MARK: - Authorities
+
+    let wizard: WizardViewModel
+    let environment: AppEnvironment
+
+    // MARK: - Settings-driven thresholds
+
+    private(set) var goodMax: Double = 2.0
+    private(set) var warningMax: Double = 5.0
+    private(set) var enableLEDs: Bool = false
+
+    // MARK: - Instrument detection
+
+    var instruments: [InstrumentDevice] = []
+    var selectedInstrument: InstrumentSelection = .auto
+    var isDetecting = false
+    var detectionError: String?
+
+    // MARK: - Chartread session
+
+    var isChartreadRunning = false
+    var chartreadState: ChartreadState = .idle
+    var currentPrompt: String?
+    var requestedWarningKey: String?
+    var chartreadLog: [String] = []
+    var rows: [ChartreadRow] = []
+    var swatchRows: [SwatchRow] = []
+    var showRemoveSheetNotice = false
+    var lastError: String?
+    private var chartreadTask: Task<Void, Never>?
+
+    // MARK: - Averaging
+
+    var passSnapshots: [URL] = []
+    var isFinishing = false
+    var finishNotice: String?
+    var finishNoticeIsError = false
+    var resumedFromTi2 = false
+
+    init(wizard: WizardViewModel, environment: AppEnvironment) {
+        self.wizard = wizard
+        self.environment = environment
+        loadSettings()
+        discoverPassSnapshots()
+    }
+
+    // MARK: - Derived state
+
+    var basename: String { wizard.basename }
+    var workingDirectory: URL? { wizard.effectiveWorkingDirectory }
+
+    var canDetect: Bool { !isDetecting }
+
+    var canStartRead: Bool {
+        !basename.isEmpty && workingDirectory != nil && !isChartreadRunning
+    }
+
+    var canMeasureAnotherSheet: Bool {
+        isFinished && !passSnapshots.isEmpty
+    }
+
+    var canFinish: Bool {
+        isFinished && !passSnapshots.isEmpty
+    }
+
+    var isFinished: Bool {
+        chartreadState == .allStripsRead || chartreadState == .finished
+    }
+
+    var xyStep: XYStep {
+        if showRemoveSheetNotice { return .remove }
+        switch chartreadState {
+        case .tablePlaceSheet:
+            return .place
+        case .tableAlign:
+            return .align
+        case .reading, .awaitingStrip:
+            return .scan
+        default:
+            return .place
+        }
+    }
+
+    var hasCanonicalTi3: Bool {
+        guard let cwd = workingDirectory else { return false }
+        let url = cwd.appendingPathComponent("\(basename).ti3")
+        return FileManager.default.fileExists(atPath: url.path)
+    }
+
+    // MARK: - Settings
+
+    func loadSettings() {
+        let settings = environment.settingsStore.load()
+        goodMax = settings.deltaEGoodMax
+        warningMax = settings.deltaEWarningMax
+        enableLEDs = settings.enableI1Pro2Leds
+    }
+
+    // MARK: - Instrument detection
+
+    func detectInstruments() {
+        guard !isDetecting else { return }
+        isDetecting = true
+        detectionError = nil
+
+        Task { @MainActor [weak self] in
+            guard let self else { return }
+            do {
+                let devices = try await self.environment.runner.detectInstruments()
+                self.instruments = devices
+                if case .device(let selected) = self.selectedInstrument,
+                   !devices.contains(where: { $0.port == selected.port }) {
+                    self.selectedInstrument = .auto
+                }
+            } catch {
+                self.detectionError = error.localizedDescription
+            }
+            self.isDetecting = false
+        }
+    }
+
+    // MARK: - Chartread lifecycle
+
+    func startRead() {
+        guard canStartRead, let cwd = workingDirectory else { return }
+        let config = buildChartreadConfig(cwd: cwd)
+        startChartread(config: config)
+    }
+
+    func measureAnotherSheet() {
+        guard let cwd = workingDirectory, isFinished else { return }
+        let config = buildChartreadConfig(cwd: cwd)
+        startChartread(config: config)
+    }
+
+    private func buildChartreadConfig(cwd: URL) -> ChartreadConfig {
+        ChartreadConfig(
+            basename: basename,
+            workingDirectory: cwd,
+            selectedPort: selectedInstrument.chartreadPort,
+            enableLEDs: enableLEDs,
+            isXY: selectedInstrument.isXY
+        )
+    }
+
+    private func startChartread(config: ChartreadConfig) {
+        guard !isChartreadRunning else { return }
+
+        isChartreadRunning = true
+        chartreadState = .idle
+        currentPrompt = nil
+        lastError = nil
+        chartreadLog.removeAll()
+
+        // Optional: reset rows when starting a fresh first pass.
+        if passSnapshots.isEmpty {
+            rows.removeAll()
+            swatchRows.removeAll()
+        }
+
+        let stream = environment.runner.runChartread(config: config)
+
+        chartreadTask = Task { @MainActor [weak self] in
+            guard let self else { return }
+            for await event in stream {
+                self.handle(event: event)
+            }
+            self.isChartreadRunning = false
+        }
+    }
+
+    private func handle(event: ChartreadEvent) {
+        switch event {
+        case .prompt(let result):
+            chartreadState = result.state
+            currentPrompt = promptText(for: result)
+            requestedWarningKey = result.requestedWarningKey
+            showRemoveSheetNotice = result.isRemoveSheetNotice
+
+        case .row(let row):
+            upsert(row: row)
+            if row.isFinalRow {
+                chartreadState = .allStripsRead
+            }
+
+        case .log(let batch):
+            chartreadLog.append(contentsOf: batch)
+
+        case .removeSheetNotice:
+            showRemoveSheetNotice = true
+
+        case .exit(let code):
+            if code != 0 {
+                lastError = "chartread exited with code \(code)"
+            }
+
+        case .completed(let canonicalURL):
+            chartreadState = .finished
+            completePass(canonicalURL: canonicalURL)
+
+        case .failed(let error):
+            lastError = error.localizedDescription
+            chartreadState = .error
+            isChartreadRunning = false
+        }
+    }
+
+    private func promptText(for result: ChartreadClassifyResult) -> String {
+        switch result.state {
+        case .calibrating:
+            return "Place instrument on calibration tile and press Calibrate."
+        case .awaitingStrip:
+            return "Press a key to read the next strip."
+        case .allStripsRead:
+            return "All strips read. Press Done & Save when ready."
+        case .warning:
+            if let key = result.requestedWarningKey {
+                return "Warning — press '\(key.uppercased())' to continue."
+            }
+            return "Warning — press Continue."
+        case .promptContinue:
+            return "Press Continue."
+        case .tablePlaceSheet:
+            if let n = result.sheetNumber, let t = result.sheetTotal {
+                return "Place sheet \(n) of \(t) on the table."
+            }
+            return "Place the sheet on the table."
+        case .tableAlign:
+            if let patch = result.alignmentPatch {
+                return "Locate patch \(patch) with the sight, then continue."
+            }
+            return "Align the fiducial, then continue."
+        case .reading:
+            return "Reading..."
+        case .error:
+            return "Read error — you can Retry or Cancel."
+        case .finished:
+            return "Measurement saved."
+        case .idle:
+            return "Press Start to begin reading."
+        }
+    }
+
+    // MARK: - User actions
+
+    func calibrate() {
+        send(.trigger)
+    }
+
+    func accept() {
+        if let key = requestedWarningKey {
+            send(.customKey(key))
+            requestedWarningKey = nil
+        } else {
+            send(.accept)
+        }
+    }
+
+    func retry() {
+        send(.trigger)
+    }
+
+    func doneAndSave() {
+        send(.done)
+    }
+
+    func cancelRead() {
+        environment.runner.cancelChartread(basename: basename, isXY: selectedInstrument.isXY)
+        chartreadTask?.cancel()
+        isChartreadRunning = false
+        chartreadState = .idle
+        currentPrompt = nil
+        requestedWarningKey = nil
+        showRemoveSheetNotice = false
+    }
+
+    func sendWarningKey(_ key: String) {
+        send(.customKey(key))
+    }
+
+    private func send(_ input: ChartreadInput) {
+        Task { @MainActor [weak self] in
+            guard let self, self.isChartreadRunning else { return }
+            try? await self.environment.runner.sendChartreadInput(basename: self.basename, input: input)
+        }
+    }
+
+    // MARK: - Rows and swatches
+
+    private func upsert(row: ChartreadRow) {
+        if let index = rows.firstIndex(where: { $0.rowIndex == row.rowIndex }) {
+            rows[index] = row
+        } else {
+            rows.append(row)
+        }
+        rows.sort { $0.rowIndex < $1.rowIndex }
+        recomputeSwatches()
+    }
+
+    func recomputeSwatches() {
+        var displayRows: [SwatchRow] = []
+        for (rowIndex, row) in rows.enumerated() {
+            var swatches: [Swatch] = []
+            for patch in row.patches {
+                let skip = shouldSkipPad(patch)
+                if skip { continue }
+
+                let eval = ColorDifference.evaluate(
+                    patch: patch,
+                    goodMax: goodMax,
+                    warningMax: warningMax
+                )
+                if let eval {
+                    swatches.append(Swatch(
+                        rowId: row.rowId,
+                        loc: patch.loc,
+                        isPad: patch.isPad,
+                        intended: eval.intended,
+                        measured: eval.measured,
+                        deltaE: eval.deltaE,
+                        classification: eval.classification
+                    ))
+                }
+            }
+            if !swatches.isEmpty {
+                displayRows.append(SwatchRow(index: rowIndex, rowId: row.rowId, patches: swatches))
+            }
+        }
+        swatchRows = displayRows
+    }
+
+    private func shouldSkipPad(_ patch: ChartreadPatch) -> Bool {
+        guard patch.isPad else { return false }
+        let measuredEmpty = patch.measured.xyz == nil && patch.measured.lab == nil
+        let deviceAllZero = patch.device.allSatisfy { $0 == 0 }
+        return measuredEmpty && deviceAllZero
+    }
+
+    // MARK: - Pass management
+
+    private func completePass(canonicalURL: URL) {
+        guard let cwd = workingDirectory else { return }
+        do {
+            _ = try MeasurementArtefacts.snapshotPass(basename: basename, cwd: cwd)
+            discoverPassSnapshots()
+            wizard.refreshGating()
+        } catch {
+            lastError = "Could not snapshot pass: \(error.localizedDescription)"
+        }
+    }
+
+    func discoverPassSnapshots() {
+        guard let cwd = workingDirectory else {
+            passSnapshots = []
+            return
+        }
+        passSnapshots = MeasurementArtefacts.passSnapshots(basename: basename, cwd: cwd)
+    }
+
+    // MARK: - Finish / Average
+
+    func finishAndAverage() {
+        guard !isFinishing, let cwd = workingDirectory, !passSnapshots.isEmpty else { return }
+        isFinishing = true
+        finishNotice = nil
+        finishNoticeIsError = false
+
+        Task { @MainActor [weak self] in
+            guard let self else { return }
+            do {
+                let canonical: URL
+                if self.passSnapshots.count == 1, let pass = self.passSnapshots.first {
+                    canonical = try MeasurementArtefacts.promotePass(
+                        pass: pass,
+                        basename: self.basename,
+                        cwd: cwd
+                    )
+                } else {
+                    let config = AverageConfig(
+                        workingDirectory: cwd,
+                        basename: self.basename,
+                        passFiles: self.passSnapshots
+                    )
+                    canonical = try await self.environment.runner.runAverage(
+                        config: config,
+                        onLogBatch: { [weak self] batch in
+                            Task { @MainActor [weak self] in
+                                self?.chartreadLog.append(contentsOf: batch)
+                            }
+                        }
+                    )
+                }
+                self.discoverPassSnapshots()
+                self.wizard.refreshGating()
+                if self.wizard.isUnlocked(.buildProfile) {
+                    self.wizard.go(to: .buildProfile)
+                } else {
+                    self.finishNotice = "Finished: \(canonical.lastPathComponent) ready."
+                }
+            } catch {
+                // Fallback to pass 1 promotion if averaging failed.
+                if let pass = self.passSnapshots.first {
+                    do {
+                        _ = try MeasurementArtefacts.promotePass(
+                            pass: pass,
+                            basename: self.basename,
+                            cwd: cwd
+                        )
+                        self.discoverPassSnapshots()
+                        self.wizard.refreshGating()
+                        self.finishNotice = "Averaging failed — promoted first pass."
+                        self.finishNoticeIsError = true
+                    } catch {
+                        self.finishNotice = "Finish failed: \(error.localizedDescription)"
+                        self.finishNoticeIsError = true
+                    }
+                } else {
+                    self.finishNotice = "Finish failed: \(error.localizedDescription)"
+                    self.finishNoticeIsError = true
+                }
+            }
+            self.isFinishing = false
+        }
+    }
+}

Sources/ICCery/NoticeBanner.swift

@@ -43,6 +43,7 @@ struct NoticeBanner: View {
                 .foregroundStyle(Theme.text)
                 .lineLimit(3)
                 .accessibilityIdentifier("noticeText")
+                .accessibilityValue(notice.text)
             Spacer()
             Button(action: onClose) {
                 Image(systemName: "xmark")

Sources/ICCery/ProfileWorkflowViewModel.swift

@@ -0,0 +1,506 @@
+import Foundation
+import Observation
+import SwiftUI
+import ICCeryCore
+
+/// User-facing FWA selection for the Stage 4 form.
+enum ColprofFwaSelection: String, CaseIterable, Sendable, Equatable {
+    case none = "none"
+    case empty = ""
+    case D50 = "D50"
+    case D65 = "D65"
+    case custom = "custom"
+
+    var displayName: String {
+        switch self {
+        case .none: return "None"
+        case .empty: return "Bare (-f)"
+        case .D50: return "D50"
+        case .D65: return "D65"
+        case .custom: return "Custom .sp"
+        }
+    }
+}
+
+/// Stage 4/5 workflow: build a profile, verify it, track drift, and install.
+@MainActor
+@Observable
+final class ProfileWorkflowViewModel {
+
+    let wizard: WizardViewModel
+    let environment: AppEnvironment
+    private let fileDialogs = FileDialogService.shared
+
+    // MARK: - Stage 4 form
+
+    var algorithm: String = "l"      // l | x | X | m
+    var quality: String = "m"        // l | m | h | u
+    var intent: String = ""          // usually empty at Stage 4
+    var fwaSelection: ColprofFwaSelection = .none
+    var fwaCustomPath: String = ""
+    var illuminant: String = ""
+    var observer: String = ""
+    var inputViewingCond: String = ""
+    var outputViewingCond: String = ""
+    var profileDescription: String = ""
+    var copyright: String = ""
+
+    // MARK: - Run state
+
+    var isColprofRunning = false
+    var colprofLog: [String] = []
+    var colprofProgress: String?
+    var lastError: String?
+    var createdProfileURL: URL?
+
+    // MARK: - Stage 4/5 calibration (issue #24)
+
+    var applyCalibration = false
+    var calibrationFile: String = ""
+
+    // MARK: - Stage 5 verification (issue #25)
+
+    var profcheckReport: ProfcheckReport?
+    var profcheckWarning: String?
+    var isProfcheckRunning = false
+
+    // MARK: - History / drift (issue #26)
+
+    var verificationHistory: [VerificationRecord] = []
+    var driftPrinterFilter: String? = nil
+    var driftAlert: String?
+    var isHistoryStoreError: String?
+
+    // MARK: - Install (issue #27)
+
+    var installResult: InstallProfileResult?
+    var showingInstallCollision = false
+    var installCollisionMessage: String = ""
+    var pendingInstallOptions: InstallProfileOptions?
+
+    init(wizard: WizardViewModel, environment: AppEnvironment) {
+        self.wizard = wizard
+        self.environment = environment
+        restoreCreatedProfileURL()
+    }
+
+    /// Restores `createdProfileURL` from the wizard artefacts or by probing
+    /// the working directory for an existing `.icc`/`.icm` (#52).
+    func restoreCreatedProfileURL() {
+        let cwd = wizard.effectiveWorkingDirectory ?? PathSecurity.resolveSafeCwd(nil)
+        createdProfileURL = wizard.artefacts.profilePath
+            ?? ArtefactProbe.resolveProfile(basename: wizard.basename, cwd: cwd)
+    }
+
+    // MARK: - Derived
+
+    var canCreateProfile: Bool {
+        !wizard.basename.isEmpty && wizard.effectiveWorkingDirectory != nil && !isColprofRunning
+    }
+
+    var canVerify: Bool {
+        createdProfileURL != nil && !isProfcheckRunning
+    }
+
+    var fwaValue: String? {
+        switch fwaSelection {
+        case .none: return nil
+        case .empty: return ""
+        case .D50: return "D50"
+        case .D65: return "D65"
+        case .custom: return fwaCustomPath
+        }
+    }
+
+    // MARK: - Preset application
+
+    func applyPreset(_ preset: ProfilingPreset?) {
+        guard let preset else { return }
+        algorithm = preset.colprofAlgorithm ?? "l"
+        quality = preset.colprofQuality ?? "m"
+        intent = preset.colprofIntent ?? ""
+
+        if let fwa = preset.colprofFwa {
+            switch fwa.lowercased() {
+            case "none": fwaSelection = .none
+            case "": fwaSelection = .empty
+            case "d50": fwaSelection = .D50
+            case "d65": fwaSelection = .D65
+            default:
+                fwaSelection = .custom
+                fwaCustomPath = fwa
+            }
+        }
+
+        illuminant = preset.colprofIlluminant ?? ""
+        observer = preset.colprofObserver ?? ""
+        inputViewingCond = preset.colprofInputViewingCond ?? ""
+        outputViewingCond = preset.colprofOutputViewingCond ?? ""
+    }
+
+    /// Stage 4 form values for saving into a custom preset.
+    func presetSnapshot() -> (
+        algorithm: String,
+        quality: String,
+        intent: String?,
+        fwa: String?,
+        illuminant: String?,
+        observer: String?,
+        inputViewingCond: String?,
+        outputViewingCond: String?
+    ) {
+        (
+            algorithm: algorithm,
+            quality: quality,
+            intent: intent.isEmpty ? nil : intent,
+            fwa: fwaValue,
+            illuminant: illuminant.isEmpty ? nil : illuminant,
+            observer: observer.isEmpty ? nil : observer,
+            inputViewingCond: inputViewingCond.isEmpty ? nil : inputViewingCond,
+            outputViewingCond: outputViewingCond.isEmpty ? nil : outputViewingCond
+        )
+    }
+
+    // MARK: - Stage 4: build profile
+
+    func buildColprofConfig() -> ColprofConfig {
+        let description = profileDescription.isEmpty ? wizard.basename : profileDescription
+        return ColprofConfig(
+            algorithm: algorithm,
+            quality: quality,
+            intent: intent.isEmpty ? nil : intent,
+            fwa: fwaValue,
+            illuminant: illuminant.isEmpty ? nil : illuminant,
+            observer: observer.isEmpty ? nil : observer,
+            inputViewingCond: inputViewingCond.isEmpty ? nil : inputViewingCond,
+            outputViewingCond: outputViewingCond.isEmpty ? nil : outputViewingCond,
+            description: description,
+            copyright: copyright.isEmpty ? nil : copyright,
+            basename: wizard.basename,
+            workingDirectory: wizard.effectiveWorkingDirectory
+        )
+    }
+
+    func createProfile() {
+        guard canCreateProfile, let _ = wizard.effectiveWorkingDirectory else { return }
+        let config = buildColprofConfig()
+
+        isColprofRunning = true
+        colprofLog = []
+        colprofProgress = nil
+        lastError = nil
+        createdProfileURL = nil
+
+        let runner = environment.runner
+        Task { @MainActor [weak self] in
+            guard let self else { return }
+            defer { self.isColprofRunning = false }
+
+            do {
+                let url = try await runner.runColprof(config: config) { [weak self] batch in
+                    Task { @MainActor [weak self] in
+                        guard let self else { return }
+                        self.colprofLog.append(contentsOf: batch)
+                        if let last = batch.last {
+                            let progress = ColprofProgressClassifier.classify(line: last)
+                            self.updateProgress(progress)
+                        }
+                    }
+                }
+
+                var finalProfileURL = url
+
+                if self.applyCalibration, !self.calibrationFile.isEmpty {
+                    let applyConfig = ApplycalConfig(
+                        calibrationPath: self.calibrationFile,
+                        inputProfileURL: url
+                    )
+                    assert(!applyConfig.unapply, "applycal unapply is not supported in v2.0")
+                    finalProfileURL = try await runner.runApplycal(config: applyConfig)
+                    self.colprofLog.append("Calibration embedded: \(self.calibrationFile)")
+                }
+
+                // Gamut extraction is best-effort for Stage 5 / M6 viewer.
+                do {
+                    let gamConfig = IccgamutConfig(profileURL: finalProfileURL)
+                    _ = try await runner.runIccgamut(config: gamConfig) { [weak self] batch in
+                        Task { @MainActor [weak self] in
+                            self?.colprofLog.append(contentsOf: batch)
+                        }
+                    }
+                    self.colprofLog.append("Gamut mesh extracted.")
+                } catch {
+                    self.wizard.showNotice(
+                        "Gamut extraction skipped: \(error.localizedDescription)",
+                        kind: .info
+                    )
+                }
+
+                self.createdProfileURL = finalProfileURL
+                self.wizard.refreshGating()
+                self.wizard.showNotice("Profile created: \(finalProfileURL.lastPathComponent)")
+                self.wizard.go(to: .verifyInstall)
+            } catch {
+                self.lastError = error.localizedDescription
+                self.wizard.showNotice(
+                    "Profile creation failed: \(error.localizedDescription)",
+                    kind: .error
+                )
+            }
+        }
+    }
+
+    private func updateProgress(_ progress: ColprofProgress) {
+        switch progress {
+        case .gamutMapping:
+            colprofProgress = "Gamut mapping calculation…"
+        case .fittingClut:
+            colprofProgress = "Fitting cLUT grid points…"
+        case .writingIcc:
+            colprofProgress = "Writing ICC profile…"
+        case .unknown:
+            break
+        }
+    }
+
+    // MARK: - Stage 5: verify profile
+
+    var knownPrinters: [String] {
+        var names = Set<String>()
+        for record in verificationHistory {
+            if record.printerName.isEmpty {
+                names.insert("Unknown")
+            } else {
+                names.insert(record.printerName)
+            }
+        }
+        return Array(names).sorted()
+    }
+
+    func loadHistory() {
+        Task { @MainActor [weak self] in
+            guard let self else { return }
+            do {
+                self.verificationHistory = try await self.environment.historyStore.load()
+                self.driftAlert = DriftAlert.compute(from: self.filteredHistory)
+            } catch {
+                self.isHistoryStoreError = error.localizedDescription
+                self.wizard.showNotice(
+                    "Could not load verification history: \(error.localizedDescription)",
+                    kind: .error
+                )
+            }
+        }
+    }
+
+    var filteredHistory: [VerificationRecord] {
+        guard let filter = driftPrinterFilter, !filter.isEmpty else {
+            return verificationHistory
+        }
+        return verificationHistory.filter { $0.printerName == filter }
+    }
+
+    func verifyProfile() {
+        guard canVerify,
+              let cwd = wizard.effectiveWorkingDirectory,
+              let profileURL = createdProfileURL else { return }
+
+        let ti3URL = ArtefactProbe.artefact(wizard.basename, "ti3", cwd)
+        let config = ProfcheckConfig(ti3URL: ti3URL, iccURL: profileURL)
+
+        isProfcheckRunning = true
+        profcheckReport = nil
+        profcheckWarning = nil
+
+        let runner = environment.runner
+        Task { @MainActor [weak self] in
+            guard let self else { return }
+            defer { self.isProfcheckRunning = false }
+
+            do {
+                let report = try await runner.runProfcheck(config: config) { [weak self] batch in
+                    Task { @MainActor [weak self] in
+                        self?.colprofLog.append(contentsOf: batch)
+                    }
+                }
+                self.profcheckReport = report
+                if let record = self.makeVerificationRecord(from: report) {
+                    let updated = try await self.environment.historyStore.append(record)
+                    self.verificationHistory = updated
+                    self.driftAlert = DriftAlert.compute(from: self.filteredHistory)
+                }
+            } catch let error as ArgyllRunnerError where error == .profcheckUnparseable {
+                self.profcheckWarning = "profcheck output could not be parsed."
+                self.profcheckReport = ProfcheckReport(warning: self.profcheckWarning)
+            } catch {
+                self.profcheckWarning = error.localizedDescription
+                self.profcheckReport = ProfcheckReport(warning: self.profcheckWarning)
+                self.wizard.showNotice(
+                    "Verification failed: \(error.localizedDescription)",
+                    kind: .error
+                )
+            }
+        }
+    }
+
+    func makeVerificationRecord(from report: ProfcheckReport) -> VerificationRecord? {
+        guard let avg = report.avgDE,
+              let max = report.maxDE,
+              let rms = report.rmsDE,
+              let status = report.status else { return nil }
+
+        let timestamp = Date()
+        let id = "vr-\(Int(timestamp.timeIntervalSince1970))-\(Self.nextSeq())"
+        let printerName = wizard.printerName?.isEmpty == false ? wizard.printerName! : "Unknown"
+        return VerificationRecord(
+            id: id,
+            profileName: createdProfileURL?.lastPathComponent ?? wizard.basename,
+            printerName: printerName,
+            avgDE: avg,
+            maxDE: max,
+            rmsDE: rms,
+            patchCount: report.patchCount ?? 0,
+            status: status,
+            timestamp: timestamp
+        )
+    }
+
+    private static func nextSeq() -> Int {
+        Int.random(in: 0..<1_000_000)
+    }
+
+    func clearHistory() {
+        Task { @MainActor [weak self] in
+            guard let self else { return }
+            do {
+                try await self.environment.historyStore.clear()
+                self.verificationHistory = []
+                self.driftAlert = nil
+            } catch {
+                self.wizard.showNotice(
+                    "Could not clear history: \(error.localizedDescription)",
+                    kind: .error
+                )
+            }
+        }
+    }
+
+    // MARK: - Profile install
+
+    func beginInstallProfile() {
+        guard let sourceURL = createdProfileURL,
+              let _ = wizard.effectiveWorkingDirectory else { return }
+
+        let settings = environment.settingsStore.load()
+        let preferSystem = settings.defaultInstallLocation == .system
+        let options = InstallProfileOptions(
+            forceOverwrite: !settings.askBeforeOverwriteProfile,
+            preferSystem: preferSystem,
+            collisionPolicy: .overwrite,
+            openColorPanel: settings.openColorPanelAfterInstall
+        )
+
+        do {
+            let config = InstallProfileConfig(sourceURL: sourceURL, options: options)
+            let destURL = try ProfileInstaller.resolveDestinationURL(for: config)
+            let collision = FileManager.default.fileExists(atPath: destURL.path)
+
+            if collision && settings.askBeforeOverwriteProfile {
+                pendingInstallOptions = options
+                installCollisionMessage = "A profile named \(destURL.lastPathComponent) already exists."
+                showingInstallCollision = true
+                return
+            }
+
+            runInstall(sourceURL: sourceURL, options: options)
+        } catch {
+            wizard.showNotice(
+                "Install failed: \(error.localizedDescription)",
+                kind: .error
+            )
+        }
+    }
+
+    func resolveInstallCollision(policy: ProfileCollisionPolicy) {
+        showingInstallCollision = false
+        guard let sourceURL = createdProfileURL,
+              var options = pendingInstallOptions else { return }
+
+        if policy == .cancel {
+            installResult = InstallProfileResult(
+                destPath: "",
+                registered: false,
+                overwritten: false,
+                renamed: false,
+                openedPanel: false,
+                message: "Install cancelled."
+            )
+            return
+        }
+
+        options.collisionPolicy = policy
+        if policy == .overwrite {
+            options.forceOverwrite = true
+        }
+        runInstall(sourceURL: sourceURL, options: options)
+    }
+
+    private func runInstall(sourceURL: URL, options: InstallProfileOptions) {
+        let config = InstallProfileConfig(sourceURL: sourceURL, options: options)
+        Task(priority: .userInitiated) { [weak self] in
+            do {
+                let result = try ProfileInstaller.install(config: config)
+                await MainActor.run { [weak self] in
+                    self?.installResult = result
+                    self?.wizard.showNotice(result.message)
+                }
+            } catch {
+                await MainActor.run { [weak self] in
+                    self?.wizard.showNotice(
+                        "Install failed: \(error.localizedDescription)",
+                        kind: .error
+                    )
+                }
+            }
+        }
+    }
+
+    func exportHistory() {
+        guard let url = fileDialogs.selectCsvSavePath() else { return }
+        Task { @MainActor [weak self] in
+            guard let self else { return }
+            let csv = await self.environment.historyStore.exportCSV()
+            do {
+                try csv.write(to: url, atomically: true, encoding: .utf8)
+                self.wizard.showNotice("History exported: \(url.lastPathComponent)")
+            } catch {
+                self.wizard.showNotice(
+                    "Export failed: \(error.localizedDescription)",
+                    kind: .error
+                )
+            }
+        }
+    }
+
+    // MARK: - File pickers
+
+    func browseForSpectrumFile() {
+        let start = wizard.effectiveWorkingDirectory
+        let url = UITestHooks.isEnabled
+            ? nil
+            : fileDialogs.selectSpectrumFile(startingAt: start)
+        if let url {
+            fwaSelection = .custom
+            fwaCustomPath = url.path
+        }
+    }
+
+    func browseForCalibrationFile() {
+        let start = wizard.effectiveWorkingDirectory
+        let url = fileDialogs.selectCalFile(startingAt: start)
+        if let url {
+            calibrationFile = url.path
+            applyCalibration = true
+        }
+    }
+}

Sources/ICCery/RootView.swift

@@ -8,6 +8,7 @@ struct RootView: View {
     @Bindable var workflow: TargetWorkflowViewModel
     @State private var showingSettings = false
     @State private var showingAbout = false
+    @State private var showingAllHelp = false
 
     private var model: WizardViewModel { workflow.wizard }
 
@@ -16,7 +17,8 @@ struct RootView: View {
             SidebarView(
                 workflow: workflow,
                 onOpenSettings: { showingSettings = true },
-                onOpenAbout: { showingAbout = true }
+                onOpenAbout: { showingAbout = true },
+                showingAllHelp: $showingAllHelp
             )
 
             Rectangle()
@@ -48,10 +50,8 @@ struct RootView: View {
         .sheet(isPresented: $workflow.showingManagePresets) {
             ManagePresetsDialog(workflow: workflow)
         }
-        .alert("ICCery 2.0.0", isPresented: $showingAbout) {
-            Button("OK") {}
-        } message: {
-            Text("Native macOS printer profiling workstation.\nFull About dialog lands in issue #31.")
+        .sheet(isPresented: $showingAbout) {
+            AboutView { showingAbout = false }
         }
     }
 
@@ -63,21 +63,11 @@ struct RootView: View {
         case .layOutPrint:
             Stage2View(workflow: workflow)
         case .measure:
-            // Stage 3 stays a shell until M4, but a .ti2 resume still
-            // lands here — show the persisted state (#8, issue #140).
-            VStack(spacing: 16) {
-                if workflow.resumedFromTi2 {
-                    Label("Resumed from .ti2", systemImage: "arrow.uturn.right")
-                        .font(.callout)
-                        .foregroundStyle(Theme.accent)
-                        .accessibilityIdentifier("stage3LoadedTargetBanner")
-                }
-                Text(model.basename)
-                    .font(.title3)
-                    .foregroundStyle(Theme.text)
-                    .accessibilityIdentifier("stage3TargetBasename")
-                StagePlaceholderView(stage: model.stage)
-            }
+            Stage3View(model: workflow.measurement)
+        case .buildProfile:
+            Stage4View(model: workflow.profile)
+        case .verifyInstall:
+            Stage5View(model: workflow.profile)
         default:
             StagePlaceholderView(stage: model.stage)
         }

Sources/ICCery/SidebarView.swift

@@ -7,6 +7,7 @@ struct SidebarView: View {
     @Bindable var workflow: TargetWorkflowViewModel
     var onOpenSettings: () -> Void
     var onOpenAbout: () -> Void
+    @Binding var showingAllHelp: Bool
 
     private var model: WizardViewModel { workflow.wizard }
 
@@ -22,12 +23,20 @@ struct SidebarView: View {
                     Image(systemName: "gearshape")
                 }
                 .buttonStyle(.plain)
-                .help("Settings")
+                .helpOverlay("Open the Settings dialog.", showing: $showingAllHelp)
+                .accessibilityIdentifier("openSettingsBtn")
                 Button(action: onOpenAbout) {
                     Image(systemName: "info.circle")
                 }
                 .buttonStyle(.plain)
-                .help("About ICCery")
+                .helpOverlay("Open the About dialog.", showing: $showingAllHelp)
+                .accessibilityIdentifier("openAboutBtn")
+                Button(action: { showingAllHelp.toggle() }) {
+                    Image(systemName: showingAllHelp ? "questionmark.circle.fill" : "questionmark.circle")
+                }
+                .buttonStyle(.plain)
+                .help("Toggle help overlays")
+                .accessibilityIdentifier("btnToggleAllHelp")
             }
             .padding(12)
 

Sources/ICCery/Stage1View.swift

@@ -87,9 +87,8 @@ struct Stage1View: View {
                 Button("Working Dir…") { workflow.browseForWorkingDirectory() }
                 Button("Open Existing…") { workflow.openExistingTarget() }
                     .accessibilityIdentifier("btnOpenExisting")
-                Button("Import Dataset…") { /* CGATS import — #94, later */ }
+                Button("Import Dataset…") { workflow.importMeasurementDataset() }
                     .accessibilityIdentifier("btn-import-dataset")
-                    .disabled(true)
             }
             Text(workflow.targetDirectory?.path ?? "No working directory selected")
                 .font(.caption)

Sources/ICCery/Stage2View.swift

@@ -230,11 +230,10 @@ struct Stage2View: View {
                         .foregroundStyle(workflow.printNoticeIsError
                                          ? .red : .secondary)
                         .accessibilityIdentifier("printNotificationText")
+                        .accessibilityValue(notice)
                 }
                 Spacer()
             }
-            .accessibilityElement(children: .contain)
-            .accessibilityIdentifier("printNotification")
 
             // Printer row: select + status + refresh + Preferences.
             HStack(spacing: 10) {

Sources/ICCery/Stage3View.swift

@@ -0,0 +1,385 @@
+import Combine
+import SwiftUI
+import ICCeryCore
+
+/// Stage 3 — measurement, live swatches, and multi-pass averaging.
+struct Stage3View: View {
+    @Bindable var model: MeasurementWorkflowViewModel
+
+    var body: some View {
+        VStack(spacing: 0) {
+            header
+            ScrollView {
+                VStack(alignment: .leading, spacing: 16) {
+                    instrumentSection
+                    chartreadControlsSection
+                    xyTableSection
+                    swatchGridSection
+                    averagingSection
+                }
+                .padding(20)
+            }
+        }
+        .frame(maxWidth: .infinity, maxHeight: .infinity)
+        .background(Theme.background)
+        .onAppear { model.discoverPassSnapshots() }
+        .onReceive(NotificationCenter.default.publisher(for: SettingsStore.settingsDidChange)) { _ in
+            model.loadSettings()
+            model.recomputeSwatches()
+        }
+    }
+
+    // MARK: - Header
+
+    @ViewBuilder
+    private var header: some View {
+        HStack(alignment: .firstTextBaseline) {
+            VStack(alignment: .leading, spacing: 4) {
+                if model.resumedFromTi2 {
+                    Label("Resumed from .ti2", systemImage: "arrow.uturn.right")
+                        .font(.callout)
+                        .foregroundStyle(Theme.accent)
+                        .accessibilityIdentifier("stage3LoadedTargetBanner")
+                }
+                Text(model.basename)
+                    .font(.title3)
+                    .foregroundStyle(Theme.text)
+                    .accessibilityIdentifier("stage3TargetBasename")
+                Text("Measure the printed chart with a spectrophotometer.")
+                    .font(.callout)
+                    .foregroundStyle(.secondary)
+                    .accessibilityIdentifier("stage3TargetMeta")
+            }
+
+            Spacer()
+
+            if model.isChartreadRunning {
+                ProgressView()
+                    .scaleEffect(0.8)
+                    .accessibilityIdentifier("readProgress")
+            }
+
+            if let badge = targetBadge {
+                Text(badge)
+                    .font(.caption)
+                    .padding(.horizontal, 8)
+                    .padding(.vertical, 4)
+                    .background(Theme.border)
+                    .cornerRadius(4)
+                    .foregroundStyle(Theme.text)
+                    .accessibilityIdentifier("stage3TargetBadge")
+            }
+        }
+        .padding(16)
+        .background(Theme.panel)
+    }
+
+    private var targetBadge: String? {
+        if model.isFinished { return "All strips read" }
+        if model.isChartreadRunning { return "Reading" }
+        if !model.passSnapshots.isEmpty { return "\(model.passSnapshots.count) pass(es)" }
+        return nil
+    }
+
+    // MARK: - Instrument detection
+
+    @ViewBuilder
+    private var instrumentSection: some View {
+        VStack(alignment: .leading, spacing: 10) {
+            HStack {
+                Text("Instrument")
+                    .font(.headline)
+                    .foregroundStyle(Theme.text)
+                Spacer()
+                Button(action: { model.detectInstruments() }) {
+                    Image(systemName: "arrow.clockwise")
+                }
+                .disabled(!model.canDetect)
+                .accessibilityIdentifier("btnDetectInstruments")
+            }
+
+            if model.detectionError != nil {
+                Text(model.detectionError ?? "")
+                    .font(.caption)
+                    .foregroundStyle(.red)
+            }
+
+            Picker("Instrument", selection: Binding(
+                get: { instrumentTag },
+                set: { newTag in
+                    if newTag.isEmpty {
+                        model.selectedInstrument = .auto
+                    } else if let device = model.instruments.first(where: { "\($0.port)" == newTag }) {
+                        model.selectedInstrument = .device(device)
+                    }
+                }
+            )) {
+                Text("Auto (first available port)").tag("")
+                ForEach(model.instruments) { device in
+                    Text(device.displayName).tag("\(device.port)")
+                }
+            }
+            .pickerStyle(.menu)
+            .accessibilityIdentifier("chartreadInstrumentSelect")
+
+            if model.selectedInstrument.isXY {
+                Text("XY table workflow selected.")
+                    .font(.caption)
+                    .foregroundStyle(Theme.accent)
+                    .accessibilityIdentifier("xyTableHint")
+            }
+        }
+        .padding(16)
+        .background(Theme.panel)
+    }
+
+    private var instrumentTag: String {
+        switch model.selectedInstrument {
+        case .auto:
+            return ""
+        case .device(let device):
+            return "\(device.port)"
+        }
+    }
+
+    // MARK: - Chartread controls
+
+    @ViewBuilder
+    private var chartreadControlsSection: some View {
+        VStack(alignment: .leading, spacing: 10) {
+            HStack {
+                Text("Status")
+                    .font(.headline)
+                    .foregroundStyle(Theme.text)
+                Spacer()
+                Text(model.currentPrompt ?? "Press Start to begin reading.")
+                    .font(.callout)
+                    .foregroundStyle(Theme.text)
+                    .accessibilityIdentifier("chartreadPrompt")
+            }
+
+            if model.showRemoveSheetNotice {
+                Text("Please remove last sheet from table.")
+                    .font(.caption)
+                    .foregroundStyle(Theme.accent)
+            }
+
+            if let lastError = model.lastError {
+                Text(lastError)
+                    .font(.caption)
+                    .foregroundStyle(.red)
+                    .accessibilityIdentifier("chartreadLastError")
+                    .accessibilityValue(lastError)
+            }
+
+            controlButtons
+
+            if !model.chartreadLog.isEmpty {
+                DisclosureGroup("Log") {
+                    VStack(alignment: .leading) {
+                        ForEach(model.chartreadLog, id: \.self) { line in
+                            Text(line)
+                                .font(.system(.caption, design: .monospaced))
+                                .foregroundStyle(.secondary)
+                        }
+                    }
+                }
+                .foregroundStyle(Theme.text)
+                .accessibilityIdentifier("chartreadLogContainer")
+            }
+        }
+        .padding(16)
+        .background(Theme.panel)
+    }
+
+    @ViewBuilder
+    private var controlButtons: some View {
+        HStack(spacing: 12) {
+            if !model.isChartreadRunning {
+                Button("Start Read") {
+                    model.startRead()
+                }
+                .disabled(!model.canStartRead)
+                .accessibilityIdentifier("btnStartRead")
+            }
+
+            if model.isChartreadRunning {
+                switch model.chartreadState {
+                case .calibrating:
+                    Button("Calibrate") { model.calibrate() }
+                        .accessibilityIdentifier("btnCalibrate")
+                case .awaitingStrip:
+                    Button("Trigger") { model.calibrate() }
+                        .accessibilityIdentifier("btnTrigger")
+                    Button("Done & Save") { model.doneAndSave() }
+                        .accessibilityIdentifier("btnDoneReadEarly")
+                case .tablePlaceSheet, .tableAlign, .promptContinue, .warning:
+                    Button(continueTitle) { model.accept() }
+                        .accessibilityIdentifier("btnAccept")
+                case .error:
+                    Button("Retry") { model.retry() }
+                        .accessibilityIdentifier("btnRetry")
+                case .allStripsRead:
+                    Button("Done & Save") { model.doneAndSave() }
+                        .accessibilityIdentifier("btnDoneRead")
+                default:
+                    EmptyView()
+                }
+
+                Button("Cancel") { model.cancelRead() }
+                    .accessibilityIdentifier("btnCancel")
+            }
+        }
+    }
+
+    private var continueTitle: String {
+        if let key = model.requestedWarningKey {
+            return "Continue (send '\(key.uppercased())')"
+        }
+        return "Continue"
+    }
+
+    // MARK: - XY table badges
+
+    @ViewBuilder
+    private var xyTableSection: some View {
+        if model.selectedInstrument.isXY {
+            HStack(spacing: 8) {
+                xyStep("Place", active: model.xyStep == .place, id: "xyStepPlace")
+                xyStep("Align", active: model.xyStep == .align, id: "xyStepAlign")
+                xyStep("Scan", active: model.xyStep == .scan, id: "xyStepScan")
+                xyStep("Remove", active: model.xyStep == .remove, id: "xyStepRemove")
+            }
+            .padding(12)
+            .background(Theme.panel)
+            .accessibilityIdentifier("xyTablePanel")
+        }
+    }
+
+    private func xyStep(_ label: String, active: Bool, id: String) -> some View {
+        Text(label)
+            .font(.caption)
+            .fontWeight(active ? .bold : .regular)
+            .padding(.horizontal, 12)
+            .padding(.vertical, 6)
+            .background(active ? Theme.accent : Theme.border)
+            .foregroundStyle(active ? Color.white : Theme.text)
+            .cornerRadius(4)
+            .accessibilityIdentifier(id)
+    }
+
+    // MARK: - Swatch grid
+
+    @ViewBuilder
+    private var swatchGridSection: some View {
+        VStack(alignment: .leading, spacing: 12) {
+            HStack {
+                Text("Swatches")
+                    .font(.headline)
+                    .foregroundStyle(Theme.text)
+                Spacer()
+                statsView
+            }
+
+            ScrollView([.horizontal, .vertical]) {
+                VStack(alignment: .leading, spacing: 2) {
+                    ForEach(model.swatchRows) { row in
+                        HStack(spacing: 2) {
+                            Text(row.rowId)
+                                .font(.caption)
+                                .foregroundStyle(.secondary)
+                                .frame(width: 24)
+                            ForEach(row.patches) { swatch in
+                                SwatchPatchView(swatch: swatch)
+                            }
+                        }
+                    }
+                }
+                .padding(8)
+            }
+            .frame(minHeight: 120, maxHeight: 360)
+            .background(Theme.panel)
+            .accessibilityIdentifier("swatchGrid")
+        }
+        .padding(16)
+        .background(Theme.background)
+    }
+
+    @ViewBuilder
+    private var statsView: some View {
+        let patches = model.swatchRows.flatMap(\.patches)
+        let valid = patches.compactMap(\.deltaE)
+        let avg = valid.isEmpty ? nil : valid.reduce(0, +) / Double(valid.count)
+        let max = valid.max() ?? 0
+
+        HStack(spacing: 12) {
+            if let avg = avg {
+                Text("avg ΔE \(String(format: "%.2f", avg))")
+                    .font(.caption)
+                    .foregroundStyle(.secondary)
+            }
+            Text("max ΔE \(String(format: "%.2f", max))")
+                .font(.caption)
+                .foregroundStyle(.secondary)
+            Text("\(patches.count) patches")
+                .font(.caption)
+                .foregroundStyle(.secondary)
+        }
+        .accessibilityIdentifier("readStats")
+    }
+
+    // MARK: - Averaging
+
+    @ViewBuilder
+    private var averagingSection: some View {
+        if !model.passSnapshots.isEmpty || model.isFinished {
+            VStack(alignment: .leading, spacing: 10) {
+                HStack {
+                    Text("Averaging")
+                        .font(.headline)
+                        .foregroundStyle(Theme.text)
+                    Spacer()
+                    Text("\(model.passSnapshots.count) pass(es)")
+                        .font(.caption)
+                        .foregroundStyle(Theme.text)
+                        .padding(.horizontal, 8)
+                        .padding(.vertical, 4)
+                        .background(Theme.border)
+                        .cornerRadius(4)
+                        .accessibilityIdentifier("passCounterBadge")
+                }
+
+                ForEach(model.passSnapshots, id: \.lastPathComponent) { url in
+                    Text(url.lastPathComponent)
+                        .font(.caption)
+                        .foregroundStyle(.secondary)
+                }
+                .accessibilityIdentifier("passesList")
+
+                HStack(spacing: 12) {
+                    Button("Measure Another Sheet") {
+                        model.measureAnotherSheet()
+                    }
+                    .disabled(!model.isFinished || model.isChartreadRunning)
+                    .accessibilityIdentifier("btnMeasureAnotherSheet")
+
+                    Button("Finish & Average") {
+                        model.finishAndAverage()
+                    }
+                    .disabled(!model.canFinish || model.isFinishing)
+                    .accessibilityIdentifier("btnFinishAndAverage")
+                }
+
+                if let notice = model.finishNotice {
+                    Text(notice)
+                        .font(.caption)
+                        .foregroundStyle(model.finishNoticeIsError ? .red : .green)
+                }
+            }
+            .padding(16)
+            .background(Theme.panel)
+            .accessibilityElement(children: .contain)
+            .accessibilityIdentifier("chartreadAveragingPanel")
+        }
+    }
+}

Sources/ICCery/Stage4View.swift

@@ -0,0 +1,195 @@
+import SwiftUI
+import ICCeryCore
+
+/// Stage 4 — build an ICC/ICM profile from the canonical `.ti3`.
+struct Stage4View: View {
+    @Bindable var model: ProfileWorkflowViewModel
+
+    var body: some View {
+        VStack(spacing: 0) {
+            header
+            ScrollView {
+                VStack(alignment: .leading, spacing: 16) {
+                    formSection
+                    runSection
+                }
+                .padding(20)
+            }
+        }
+        .frame(maxWidth: .infinity, maxHeight: .infinity)
+        .background(Theme.background)
+        .onAppear { model.restoreCreatedProfileURL() }
+    }
+
+    // MARK: - Header
+
+    @ViewBuilder
+    private var header: some View {
+        HStack(alignment: .firstTextBaseline) {
+            VStack(alignment: .leading, spacing: 4) {
+                Text(model.wizard.basename)
+                    .font(.title3)
+                    .foregroundStyle(Theme.text)
+                    .accessibilityIdentifier("stage4TargetBasename")
+                Text("Build the ICC profile from the measured .ti3.")
+                    .font(.callout)
+                    .foregroundStyle(.secondary)
+                    .accessibilityIdentifier("stage4TargetMeta")
+            }
+
+            Spacer()
+
+            if let progress = model.colprofProgress, model.isColprofRunning {
+                Text(progress)
+                    .font(.caption)
+                    .padding(.horizontal, 8)
+                    .padding(.vertical, 4)
+                    .background(Theme.border)
+                    .cornerRadius(4)
+                    .foregroundStyle(Theme.text)
+                    .accessibilityIdentifier("colprofProgress")
+            }
+        }
+        .padding(16)
+        .background(Theme.panel)
+    }
+
+    // MARK: - Form
+
+    @ViewBuilder
+    private var formSection: some View {
+        VStack(alignment: .leading, spacing: 12) {
+            Text("Profile settings")
+                .font(.headline)
+                .foregroundStyle(Theme.text)
+
+            HStack(spacing: 16) {
+                Picker("Algorithm", selection: $model.algorithm) {
+                    Text("Lab cLUT").tag("l")
+                    Text("XYZ cLUT").tag("x")
+                    Text("Display XYZ+matrix").tag("X")
+                    Text("Matrix").tag("m")
+                }
+                .accessibilityIdentifier("colprofAlgorithm")
+
+                Picker("Quality", selection: $model.quality) {
+                    Text("Low").tag("l")
+                    Text("Medium").tag("m")
+                    Text("High").tag("h")
+                    Text("Ultra").tag("u")
+                }
+                .accessibilityIdentifier("colprofQuality")
+            }
+
+            Picker("FWA / OBA compensation", selection: $model.fwaSelection) {
+                ForEach(ColprofFwaSelection.allCases, id: \.self) { selection in
+                    Text(selection.displayName).tag(selection)
+                }
+            }
+            .accessibilityIdentifier("colprofFwa")
+
+            if model.fwaSelection == .custom {
+                HStack {
+                    TextField("Custom .sp spectrum path", text: $model.fwaCustomPath)
+                        .textFieldStyle(.roundedBorder)
+                        .accessibilityIdentifier("colprofFwaCustomPath")
+                    Button("Browse…") { model.browseForSpectrumFile() }
+                        .accessibilityIdentifier("btnBrowseFwaSp")
+                }
+            }
+
+            HStack(spacing: 16) {
+                TextField("Illuminant", text: $model.illuminant)
+                    .textFieldStyle(.roundedBorder)
+                    .accessibilityIdentifier("colprofIlluminant")
+
+                TextField("Observer", text: $model.observer)
+                    .textFieldStyle(.roundedBorder)
+                    .accessibilityIdentifier("colprofObserver")
+            }
+
+            HStack(spacing: 16) {
+                TextField("Input viewing condition", text: $model.inputViewingCond)
+                    .textFieldStyle(.roundedBorder)
+                    .accessibilityIdentifier("colprofInputViewCond")
+
+                TextField("Output viewing condition", text: $model.outputViewingCond)
+                    .textFieldStyle(.roundedBorder)
+                    .accessibilityIdentifier("colprofOutputViewCond")
+            }
+
+            Text("Use 'none' to skip a viewing condition.")
+                .font(.caption)
+                .foregroundStyle(.secondary)
+
+            TextField("Description", text: $model.profileDescription)
+                .textFieldStyle(.roundedBorder)
+                .accessibilityIdentifier("colprofDescription")
+
+            TextField("Copyright", text: $model.copyright)
+                .textFieldStyle(.roundedBorder)
+                .accessibilityIdentifier("colprofCopyright")
+
+            Toggle("Apply calibration curve", isOn: $model.applyCalibration)
+                .accessibilityIdentifier("colprofApplyCalibration")
+
+            if model.applyCalibration {
+                HStack {
+                    TextField("Calibration .cal file", text: $model.calibrationFile)
+                        .textFieldStyle(.roundedBorder)
+                        .accessibilityIdentifier("colprofCalibrationFile")
+                    Button("Browse…") { model.browseForCalibrationFile() }
+                        .accessibilityIdentifier("btnBrowseCalibrationFile")
+                }
+            }
+        }
+        .padding(16)
+        .background(Theme.panel)
+    }
+
+    // MARK: - Run controls
+
+    @ViewBuilder
+    private var runSection: some View {
+        VStack(alignment: .leading, spacing: 12) {
+            HStack(spacing: 12) {
+                Button("Create Profile") {
+                    model.createProfile()
+                }
+                .disabled(!model.canCreateProfile)
+                .accessibilityIdentifier("btnCreateProfile")
+
+                if model.isColprofRunning {
+                    ProgressView()
+                        .scaleEffect(0.8)
+                        .accessibilityIdentifier("colprofProgressIndicator")
+                }
+
+                Spacer()
+
+                if let lastError = model.lastError {
+                    Text(lastError)
+                        .font(.caption)
+                        .foregroundStyle(.red)
+                        .accessibilityIdentifier("colprofLastError")
+                }
+            }
+
+            if !model.colprofLog.isEmpty {
+                DisclosureGroup("Log") {
+                    VStack(alignment: .leading) {
+                        ForEach(model.colprofLog, id: \.self) { line in
+                            Text(line)
+                                .font(.system(.caption, design: .monospaced))
+                                .foregroundStyle(.secondary)
+                        }
+                    }
+                }
+                .foregroundStyle(Theme.text)
+                .accessibilityIdentifier("colprofLogContainer")
+            }
+        }
+        .padding(16)
+        .background(Theme.panel)
+    }
+}

Sources/ICCery/Stage5View.swift

@@ -0,0 +1,275 @@
+import SwiftUI
+import ICCeryCore
+
+/// Stage 5 — verify the generated profile, track drift, and install.
+struct Stage5View: View {
+    @Bindable var model: ProfileWorkflowViewModel
+
+    var body: some View {
+        VStack(spacing: 0) {
+            header
+            ScrollView {
+                VStack(alignment: .leading, spacing: 16) {
+                    verifySection
+                    if let report = model.profcheckReport {
+                        resultSection(report: report)
+                    }
+                    historySection
+                }
+                .padding(20)
+            }
+        }
+        .frame(maxWidth: .infinity, maxHeight: .infinity)
+        .background(Theme.background)
+        .onAppear {
+            model.restoreCreatedProfileURL()
+            model.loadHistory()
+        }
+        .alert("Install profile", isPresented: $model.showingInstallCollision) {
+            Button("Overwrite", role: .destructive) {
+                model.resolveInstallCollision(policy: .overwrite)
+            }
+            .accessibilityIdentifier("profileOverwriteBtn")
+            Button("Rename") {
+                model.resolveInstallCollision(policy: .rename)
+            }
+            .accessibilityIdentifier("profileRenameBtn")
+            Button("Cancel", role: .cancel) {
+                model.resolveInstallCollision(policy: .cancel)
+            }
+            .accessibilityIdentifier("profileCancelCollisionBtn")
+        } message: {
+            Text(model.installCollisionMessage)
+                .accessibilityIdentifier("profileInstallCollisionMessage")
+        }
+    }
+
+    // MARK: - Header
+
+    @ViewBuilder
+    private var header: some View {
+        HStack(alignment: .firstTextBaseline) {
+            VStack(alignment: .leading, spacing: 4) {
+                Text(model.wizard.basename)
+                    .font(.title3)
+                    .foregroundStyle(Theme.text)
+                    .accessibilityIdentifier("stage5TargetBasename")
+                Text("Verify the profile and compare against historical results.")
+                    .font(.callout)
+                    .foregroundStyle(.secondary)
+                    .accessibilityIdentifier("stage5TargetMeta")
+            }
+
+            Spacer()
+
+            if let alert = model.driftAlert {
+                Text(alert)
+                    .font(.caption)
+                    .padding(.horizontal, 8)
+                    .padding(.vertical, 4)
+                    .background(Color.red.opacity(0.2))
+                    .cornerRadius(4)
+                    .foregroundStyle(.red)
+                    .accessibilityIdentifier("driftAlert")
+            }
+
+            if let warning = model.profcheckWarning, !warning.isEmpty {
+                Text("⚠ \(warning)")
+                    .font(.caption)
+                    .padding(.horizontal, 8)
+                    .padding(.vertical, 4)
+                    .background(Color.red.opacity(0.2))
+                    .cornerRadius(4)
+                    .foregroundStyle(.red)
+                    .accessibilityIdentifier("profcheckWarningBanner")
+            }
+        }
+        .padding(16)
+        .background(Theme.panel)
+    }
+
+    // MARK: - Verify
+
+    @ViewBuilder
+    private var verifySection: some View {
+        VStack(alignment: .leading, spacing: 12) {
+            HStack(spacing: 12) {
+                Button("Verify Profile") {
+                    model.verifyProfile()
+                }
+                .disabled(!model.canVerify)
+                .accessibilityIdentifier("btnVerifyProfile")
+
+                if model.isProfcheckRunning {
+                    ProgressView()
+                        .scaleEffect(0.8)
+                        .accessibilityIdentifier("profcheckProgressIndicator")
+                }
+
+                Spacer()
+
+                if let profileURL = model.createdProfileURL {
+                    Text(profileURL.lastPathComponent)
+                        .font(.caption)
+                        .foregroundStyle(.secondary)
+                        .accessibilityIdentifier("stage5ProfilePath")
+                }
+            }
+
+            if !model.colprofLog.isEmpty {
+                DisclosureGroup("Log") {
+                    VStack(alignment: .leading) {
+                        ForEach(model.colprofLog, id: \.self) { line in
+                            Text(line)
+                                .font(.system(.caption, design: .monospaced))
+                                .foregroundStyle(.secondary)
+                        }
+                    }
+                }
+                .foregroundStyle(Theme.text)
+                .accessibilityIdentifier("profcheckLogContainer")
+            }
+        }
+        .padding(16)
+        .background(Theme.panel)
+    }
+
+    // MARK: - Result cards
+
+    @ViewBuilder
+    private func resultSection(report: ProfcheckReport) -> some View {
+        VStack(alignment: .leading, spacing: 12) {
+            HStack {
+                Text("Verification result")
+                    .font(.headline)
+                    .foregroundStyle(Theme.text)
+
+                Spacer()
+
+                Button("Install Profile") { model.beginInstallProfile() }
+                    .disabled(model.createdProfileURL == nil)
+                    .accessibilityIdentifier("btnInstallProfile")
+            }
+
+            HStack(spacing: 16) {
+                metricCard(title: "Avg ΔE", value: report.avgDE)
+                metricCard(title: "Max ΔE", value: report.maxDE)
+                metricCard(title: "RMS", value: report.rmsDE)
+                metricCard(title: "Patches", value: report.patchCount.map(Double.init))
+            }
+
+            if let status = report.status {
+                HStack {
+                    Text("Status")
+                    Spacer()
+                    Text(status.displayName)
+                        .fontWeight(.semibold)
+                        .foregroundStyle(statusColor(status))
+                        .accessibilityIdentifier("profcheckStatus")
+                }
+            }
+        }
+        .padding(16)
+        .background(Theme.panel)
+    }
+
+    @ViewBuilder
+    private func metricCard(title: String, value: Double?) -> some View {
+        VStack(alignment: .leading, spacing: 4) {
+            Text(title)
+                .font(.caption)
+                .foregroundStyle(.secondary)
+            Text(value.map { String(format: "%.2f", $0) } ?? "—")
+                .font(.title3)
+                .foregroundStyle(Theme.text)
+        }
+        .frame(maxWidth: .infinity, alignment: .leading)
+    }
+
+    // MARK: - History
+
+    @ViewBuilder
+    private var historySection: some View {
+        VStack(alignment: .leading, spacing: 12) {
+            Text("History & drift")
+                .font(.headline)
+                .foregroundStyle(Theme.text)
+
+            HStack {
+                Picker("Printer", selection: Binding(
+                    get: { model.driftPrinterFilter ?? "" },
+                    set: { model.driftPrinterFilter = $0.isEmpty ? nil : $0 }
+                )) {
+                    Text("All").tag("")
+                    ForEach(model.knownPrinters, id: \.self) { printer in
+                        Text(printer.isEmpty ? "Unknown" : printer).tag(printer)
+                    }
+                }
+                .accessibilityIdentifier("driftPrinterFilter")
+                .frame(width: 200)
+
+                Spacer()
+
+                Button("Export CSV") { model.exportHistory() }
+                    .accessibilityIdentifier("btnExportHistory")
+
+                Button("Clear") { model.clearHistory() }
+                    .accessibilityIdentifier("btnClearHistory")
+            }
+
+            driftChart
+
+            if !model.filteredHistory.isEmpty {
+                Table(of: VerificationRecord.self) {
+                    TableColumn("Date") { record in
+                        Text(record.timestamp.formatted(date: .numeric, time: .shortened))
+                    }
+                    TableColumn("Profile") { record in
+                        Text(record.profileName)
+                    }
+                    TableColumn("Avg") { record in
+                        Text(String(format: "%.2f", record.avgDE))
+                    }
+                    TableColumn("Max") { record in
+                        Text(String(format: "%.2f", record.maxDE))
+                    }
+                    TableColumn("RMS") { record in
+                        Text(String(format: "%.2f", record.rmsDE))
+                    }
+                    TableColumn("Status") { record in
+                        Text(record.status.displayName)
+                            .foregroundStyle(statusColor(record.status))
+                    }
+                } rows: {
+                    ForEach(model.filteredHistory) { record in
+                        TableRow(record)
+                    }
+                }
+                .frame(minHeight: 120)
+                .accessibilityIdentifier("verificationHistoryTable")
+            } else {
+                Text("No verification records yet.")
+                    .font(.callout)
+                    .foregroundStyle(.secondary)
+            }
+        }
+        .padding(16)
+        .background(Theme.panel)
+    }
+
+    @ViewBuilder
+    private var driftChart: some View {
+        let records = model.filteredHistory.sorted { $0.timestamp < $1.timestamp }
+        DriftChartView(records: records)
+            .frame(height: 160)
+            .accessibilityIdentifier("driftChart")
+    }
+
+    private func statusColor(_ status: VerificationStatus) -> Color {
+        switch status {
+        case .excellent, .good: return .green
+        case .acceptable: return .yellow
+        case .poor: return .red
+        }
+    }
+}

Sources/ICCery/SwatchPatchView.swift

@@ -0,0 +1,75 @@
+import SwiftUI
+import ICCeryCore
+
+private extension DisplayRGB {
+    var color: Color {
+        Color(red: r, green: g, blue: b)
+    }
+}
+
+/// One swatch in the live grid, with a 135° intended/measured diagonal split.
+struct SwatchPatchView: View {
+    let swatch: Swatch
+
+    private var indicatorColor: Color {
+        switch swatch.classification {
+        case .good: return .green
+        case .warning: return .yellow
+        case .bad: return .red
+        }
+    }
+
+    var body: some View {
+        ZStack {
+            // Background: measured
+            swatch.measured.color
+                .clipShape(DiagonalClip(side: .bottomRight))
+
+            // Foreground: intended
+            swatch.intended.color
+                .clipShape(DiagonalClip(side: .topLeft))
+
+            // Classification dot
+            Circle()
+                .fill(indicatorColor)
+                .frame(width: 6, height: 6)
+                .offset(x: 6, y: 6)
+        }
+        .frame(width: 32, height: 32)
+        .overlay(
+            Rectangle()
+                .stroke(Color.primary.opacity(0.2), lineWidth: 0.5)
+        )
+        .accessibilityIdentifier("swatch-\(swatch.rowId)\(swatch.loc)")
+        .accessibilityLabel("\(swatch.loc) intended \(String(format: "%.0f", swatch.intended.r * 255)), measured \(String(format: "%.0f", swatch.measured.r * 255))")
+    }
+}
+
+/// 135° diagonal clipping: top-left or bottom-right triangle.
+///
+/// A 135° line from the top-right corner to the bottom-left corner gives
+/// top-left and bottom-right triangles.
+private enum DiagonalSide {
+    case topLeft
+    case bottomRight
+}
+
+private struct DiagonalClip: Shape {
+    let side: DiagonalSide
+
+    func path(in rect: CGRect) -> Path {
+        var path = Path()
+        switch side {
+        case .topLeft:
+            path.move(to: CGPoint(x: rect.minX, y: rect.minY))
+            path.addLine(to: CGPoint(x: rect.maxX, y: rect.minY))
+            path.addLine(to: CGPoint(x: rect.minX, y: rect.maxY))
+        case .bottomRight:
+            path.move(to: CGPoint(x: rect.maxX, y: rect.minY))
+            path.addLine(to: CGPoint(x: rect.maxX, y: rect.maxY))
+            path.addLine(to: CGPoint(x: rect.minX, y: rect.maxY))
+        }
+        path.closeSubpath()
+        return path
+    }
+}

Sources/ICCery/TargetWorkflowViewModel.swift

@@ -119,9 +119,24 @@ final class TargetWorkflowViewModel {
     var savePresetName = ""
     var savePresetDesc = ""
 
+    /// Stage 3 measurement workflow, owned at the app level so it persists
+    /// across stage switches and can observe settings changes.
+    var measurement: MeasurementWorkflowViewModel
+    /// Stage 4/5 profile workflow, owned at the app level so it persists
+    /// across stage switches and can apply preset values.
+    var profile: ProfileWorkflowViewModel
+
     init(environment: AppEnvironment = .live()) {
         self.environment = environment
         self.wizard = WizardViewModel(stateStore: environment.stateStore)
+        self.measurement = MeasurementWorkflowViewModel(
+            wizard: wizard,
+            environment: environment
+        )
+        self.profile = ProfileWorkflowViewModel(
+            wizard: wizard,
+            environment: environment
+        )
         reloadPresets()
     }
 
@@ -228,6 +243,43 @@ final class TargetWorkflowViewModel {
 
     // MARK: - Issue 8: resume an existing target
 
+    /// `#btn-import-dataset` — open a measured dataset, write a canonical
+    /// `.ti3` to the working directory, and set the target (issue #30).
+    func importMeasurementDataset() {
+        let url = UITestHooks.isEnabled
+            ? UITestHooks.datasetImportURL
+            : fileDialogs.selectDatasetFile()
+        guard let url else { return }
+
+        do {
+            let dataset = try CGATSParser.parse(url: url)
+            guard let directory = targetDirectory ?? wizard.effectiveWorkingDirectory else {
+                wizard.showNotice("Choose a working directory before importing.", kind: .warning)
+                return
+            }
+
+            let stem = url.deletingPathExtension().lastPathComponent
+            let output = directory.appendingPathComponent("\(stem).ti3")
+            try CGATSWriter.write(dataset, to: output)
+
+            wizard.setTarget(basename: stem, workingDirectory: directory)
+            wizard.refreshGating()
+            wizard.showNotice("Imported \(dataset.samples.count) patches from \(url.lastPathComponent)")
+
+            if wizard.isUnlocked(.verifyInstall) {
+                wizard.go(to: .verifyInstall)
+            } else if wizard.isUnlocked(.buildProfile) {
+                wizard.go(to: .buildProfile)
+            } else {
+                wizard.showNotice("Imported dataset is not ready for profiling.", kind: .warning)
+            }
+        } catch let error as CGATSParseError {
+            wizard.showNotice("Import failed: \(error.localizedDescription)", kind: .error)
+        } catch {
+            wizard.showNotice("Import failed: \(error.localizedDescription)", kind: .error)
+        }
+    }
+
     /// `#btnOpenExisting` — open `.ti1`/`.ti2` (open dialog, #103).
     /// `.ti1` → Stage 2; `.ti2` → Stage 3 with the resume notice, but
     /// only when the sibling `.ti1` exists so the artefact gate holds.
@@ -249,6 +301,7 @@ final class TargetWorkflowViewModel {
             wizard.setTarget(basename: stem, workingDirectory: dir)
             wizard.refreshGating()
             resumedFromTi2 = false
+            measurement.resumedFromTi2 = false
             wizard.go(to: .layOutPrint)
         case "ti2":
             let header = Ti2Header.parse(url)
@@ -261,6 +314,7 @@ final class TargetWorkflowViewModel {
             wizard.setTarget(basename: stem, workingDirectory: dir)
             wizard.refreshGating()
             resumedFromTi2 = true
+            measurement.resumedFromTi2 = true
             wizard.showNotice("Resumed from .ti2", kind: .info, autoHideAfter: nil)
             wizard.go(to: .measure)
         default:
@@ -411,8 +465,6 @@ final class TargetWorkflowViewModel {
         }
     }
 
-    /// `#btnPrintAll` — spool every gallery TIFF, sequentially. Stops on
-    /// the first failure so the user sees which page failed.
     /// `#btnPrintAll` — spool every gallery TIFF, sequentially. Stops on
     /// the first failure so the user sees which page failed.
     func printAllPages() {
@@ -527,6 +579,8 @@ final class TargetWorkflowViewModel {
         }
         customSeed = preset.randomSeed ?? 1
 
+        profile.applyPreset(preset)
+
         selectedPresetID = preset.id
     }
 
@@ -563,7 +617,17 @@ final class TargetWorkflowViewModel {
             bitDepth: bitDepth.rawValue,
             dpi: tiffDpi,
             randomSeed: layoutOrder == .deterministic ? 1 : customSeed,
-            noRandomize: layoutOrder == .raster
+            noRandomize: layoutOrder == .raster,
+            calibrationFile: profile.calibrationFile.isEmpty ? nil : profile.calibrationFile,
+            applyCalibration: profile.applyCalibration ? true : nil,
+            colprofAlgorithm: profile.algorithm,
+            colprofQuality: profile.quality,
+            colprofIntent: profile.intent.isEmpty ? nil : profile.intent,
+            colprofFwa: profile.fwaValue,
+            colprofIlluminant: profile.illuminant.isEmpty ? nil : profile.illuminant,
+            colprofObserver: profile.observer.isEmpty ? nil : profile.observer,
+            colprofInputViewingCond: profile.inputViewingCond.isEmpty ? nil : profile.inputViewingCond,
+            colprofOutputViewingCond: profile.outputViewingCond.isEmpty ? nil : profile.outputViewingCond
         )
         do {
             try environment.presetStore.saveCustom(preset)

Tests/ICCeryCoreTests/ApplycalArgsTests.swift

@@ -0,0 +1,30 @@
+import Foundation
+import Testing
+@testable import ICCeryCore
+
+@Suite("ApplycalArgs")
+struct ApplycalArgsTests {
+
+    @Test("Apply argv")
+    func applyArgv() throws {
+        let config = ApplycalConfig(
+            calibrationPath: "/tmp/cal.cal",
+            inputProfileURL: URL(fileURLWithPath: "/tmp/profile.icc")
+        )
+        let args = try ApplycalArgs.build(config: config)
+        #expect(args == ["-v", "-a", "/tmp/cal.cal", "/tmp/profile.icc"])
+    }
+
+    @Test("Unapply is emitted when the caller explicitly sets it")
+    func unapplyEmittedWhenConfigSet() throws {
+        let config = ApplycalConfig(
+            calibrationPath: "/tmp/cal.cal",
+            inputProfileURL: URL(fileURLWithPath: "/tmp/profile.icc"),
+            unapply: true
+        )
+        let args = try ApplycalArgs.build(config: config)
+        // Builder emits -u only when the caller explicitly sets unapply.
+        // The UI layer never passes unapply: true in v2.0.
+        #expect(args == ["-v", "-u", "/tmp/cal.cal", "/tmp/profile.icc"])
+    }
+}

Tests/ICCeryCoreTests/ArgyllRunnerColprofTests.swift

@@ -0,0 +1,52 @@
+import Foundation
+import Testing
+@testable import ICCeryCore
+
+final class LogHolder: @unchecked Sendable {
+    private let lock = NSLock()
+    private var _lines: [String] = []
+
+    func append(_ batch: [String]) {
+        lock.lock()
+        _lines.append(contentsOf: batch)
+        lock.unlock()
+    }
+
+    var lines: [String] {
+        lock.lock()
+        defer { lock.unlock() }
+        return _lines
+    }
+}
+
+@Suite("ArgyllRunner colprof")
+struct ArgyllRunnerColprofTests {
+
+    @Test("Mock colprof produces .icc")
+    func colprofProducesIcc() async throws {
+        let binDir = URL(fileURLWithPath: #filePath)
+            .deletingLastPathComponent()
+            .deletingLastPathComponent()
+            .appendingPathComponent("ICCeryUITests/Fixtures/bin")
+        let testRoot = FileManager.default.temporaryDirectory
+            .appendingPathComponent("colprof-test-\(UUID().uuidString)")
+        try FileManager.default.createDirectory(at: testRoot, withIntermediateDirectories: true)
+
+        let runner = ArgyllRunner(
+            processManager: .shared,
+            binaryResolver: BinaryResolver(overrideDir: binDir)
+        )
+
+        let holder = LogHolder()
+        let config = ColprofConfig(basename: "testrun", workingDirectory: testRoot)
+        let url = try await runner.runColprof(config: config) { batch in
+            holder.append(batch)
+        }
+
+        #expect(url.lastPathComponent == "testrun.icc")
+        #expect(FileManager.default.fileExists(atPath: url.path))
+        #expect(holder.lines.contains { $0.contains("Gamut mapping") })
+
+        try? FileManager.default.removeItem(at: testRoot)
+    }
+}

Tests/ICCeryCoreTests/CGATSParserTests.swift

@@ -0,0 +1,134 @@
+import Foundation
+import Testing
+@testable import ICCeryCore
+
+@Suite("CGATS Parser & Writer")
+struct CGATSParserTests {
+
+    private static let canonicalCTI3 = """
+    CTI3
+    DESCRIPTOR "Sample target"
+    COLOR_REP "RGB"
+    DEVICE_CLASS "DISPLAY"
+    NUMBER_OF_FIELDS 11
+    NUMBER_OF_SETS 2
+    BEGIN_DATA_FORMAT
+    SAMPLE_ID\tSAMPLE_LOC\tRGB_R\tRGB_G\tRGB_B\tXYZ_X\tXYZ_Y\tXYZ_Z\tLAB_L\tLAB_A\tLAB_B
+    END_DATA_FORMAT
+    BEGIN_DATA
+    1\tA1\t50.0\t0.0\t0.0\t20.0\t10.0\t5.0\t50.0\t60.0\t30.0
+    2\tA2\t0.0\t50.0\t0.0\t10.0\t30.0\t5.0\t60.0\t-50.0\t40.0
+    END_DATA
+    """
+
+    @Test("Parses CTI3 with canonical field names")
+    func parseCTI3() throws {
+        let dataset = try CGATSParser.parse(Self.canonicalCTI3)
+        #expect(dataset.format == .cti3)
+        #expect(dataset.samples.count == 2)
+        #expect(dataset.colorRep == "RGB")
+        #expect(dataset.deviceClass == "DISPLAY")
+        #expect(dataset.samples[0].id == "1")
+        #expect(dataset.samples[0].loc == "A1")
+        #expect(dataset.samples[1].values["RGB_G"] == "50.0000")
+    }
+
+    @Test("Round-trips parse, write, reparse")
+    func roundTrip() throws {
+        let first = try CGATSParser.parse(Self.canonicalCTI3)
+        let text = try CGATSWriter.write(first)
+        let second = try CGATSParser.parse(text)
+        #expect(second.format == first.format)
+        #expect(second.samples.count == first.samples.count)
+        #expect(second.colorRep == first.colorRep)
+        #expect(second.deviceClass == first.deviceClass)
+    }
+
+    @Test("Parses CSV with comma delimiters")
+    func parseCSV() throws {
+        let csv = """
+        SAMPLE_ID,SAMPLE_LOC,RGB_R,RGB_G,RGB_B,XYZ_X,XYZ_Y,XYZ_Z,LAB_L,LAB_A,LAB_B
+        1,A1,50,0,0,20,10,5,50,60,30
+        2,A2,0,50,0,10,30,5,60,-50,40
+        """
+        let dataset = try CGATSParser.parse(csv, sourceURL: URL(fileURLWithPath: "/tmp/sample.csv"))
+        #expect(dataset.format == .csv)
+        #expect(dataset.samples.count == 2)
+        #expect(dataset.samples[0].values["RGB_R"] == "50.0000")
+    }
+
+    @Test("Converts 0-255 device values to 0-100")
+    func converts255To100() throws {
+        let rgb = """
+        CTI3
+        COLOR_REP RGB
+        NUMBER_OF_FIELDS 6
+        NUMBER_OF_SETS 1
+        BEGIN_DATA_FORMAT
+        SAMPLE_ID RGB_R RGB_G RGB_B XYZ_X XYZ_Y
+        END_DATA_FORMAT
+        BEGIN_DATA
+        1 255 128 0 50 25
+        END_DATA
+        """
+        let dataset = try CGATSParser.parse(rgb)
+        #expect(dataset.samples[0].values["RGB_R"] == "100.0000")
+        #expect(dataset.samples[0].values["RGB_G"] == "50.1961")
+    }
+
+    @Test("Synthesizes COLOR_REP and DEVICE_CLASS when missing")
+    func synthesizesMetadata() throws {
+        let cmyk = """
+        CTI3
+        NUMBER_OF_FIELDS 6
+        NUMBER_OF_SETS 1
+        BEGIN_DATA_FORMAT
+        SAMPLE_ID CMYK_C CMYK_M CMYK_Y CMYK_K LAB_L
+        END_DATA_FORMAT
+        BEGIN_DATA
+        1 50 50 50 50 50
+        END_DATA
+        """
+        let dataset = try CGATSParser.parse(cmyk)
+        #expect(dataset.colorRep == "CMYK")
+        #expect(dataset.deviceClass == "PRINTER")
+    }
+
+    @Test("Rejects empty file")
+    func rejectsEmpty() {
+        #expect(throws: (any Error).self) {
+            _ = try CGATSParser.parse("")
+        }
+    }
+
+    @Test("Rejects malformed arity")
+    func rejectsArity() {
+        let bad = """
+        CTI3
+        NUMBER_OF_FIELDS 2
+        NUMBER_OF_SETS 1
+        BEGIN_DATA_FORMAT
+        SAMPLE_ID RGB_R
+        END_DATA_FORMAT
+        BEGIN_DATA
+        1
+        END_DATA
+        """
+        #expect(throws: (any Error).self) {
+            _ = try CGATSParser.parse(bad)
+        }
+    }
+
+    @Test("Writer emits valid .ti3 with tabs and required keywords")
+    func writerFormat() throws {
+        let dataset = try CGATSParser.parse(Self.canonicalCTI3)
+        let text = try CGATSWriter.write(dataset)
+        #expect(text.contains("CTI3"))
+        #expect(text.contains("BEGIN_DATA_FORMAT"))
+        #expect(text.contains("BEGIN_DATA"))
+        #expect(text.contains("END_DATA"))
+        #expect(text.contains("COLOR_REP"))
+        #expect(text.contains("DEVICE_CLASS"))
+        #expect(text.contains("\t"))
+    }
+}

Tests/ICCeryCoreTests/ColprofArgsTests.swift

@@ -0,0 +1,72 @@
+import Foundation
+import Testing
+@testable import ICCeryCore
+
+@Suite("ColprofArgs")
+struct ColprofArgsTests {
+
+    @Test("Default algorithm and quality")
+    func defaults() throws {
+        let config = ColprofConfig(basename: "target")
+        let args = try ColprofArgs.build(config: config)
+        #expect(args == ["-v", "-a", "l", "-q", "m", "target"])
+    }
+
+    @Test("FWA bare -f when empty string")
+    func fwaBareFlag() throws {
+        let config = ColprofConfig(fwa: "", basename: "target")
+        let args = try ColprofArgs.build(config: config)
+        #expect(args == ["-v", "-a", "l", "-q", "m", "-f", "target"])
+    }
+
+    @Test("FWA D50 and D65 emit -f value")
+    func fwaD50() throws {
+        let config = ColprofConfig(fwa: "D50", basename: "target")
+        let args = try ColprofArgs.build(config: config)
+        #expect(args.contains("-f"))
+        #expect(args.contains("D50"))
+        #expect(args.last == "target")
+    }
+
+    @Test("FWA none is omitted")
+    func fwaNoneOmitted() throws {
+        let config = ColprofConfig(fwa: "none", basename: "target")
+        let args = try ColprofArgs.build(config: config)
+        #expect(!args.contains("-f"))
+    }
+
+    @Test("Viewing conditions skip none")
+    func viewingCondNoneSkipped() throws {
+        let config = ColprofConfig(
+            inputViewingCond: "none",
+            outputViewingCond: "mt",
+            basename: "target"
+        )
+        let args = try ColprofArgs.build(config: config)
+        #expect(!args.contains("-c"))
+        #expect(args.contains("-d"))
+        #expect(args.contains("mt"))
+    }
+
+    @Test("Description falls back to basename when empty")
+    func descriptionFallback() throws {
+        let config = ColprofConfig(description: "", basename: "target")
+        let args = try ColprofArgs.build(config: config)
+        #expect(!args.contains("-D"))
+    }
+
+    @Test("Copyright only when non-empty")
+    func copyright() throws {
+        let config = ColprofConfig(copyright: "Gronod 2026", basename: "target")
+        let args = try ColprofArgs.build(config: config)
+        #expect(args.contains("-C"))
+        #expect(args.contains("Gronod 2026"))
+    }
+
+    @Test("No -u passed")
+    func noProgressJsonFlag() throws {
+        let config = ColprofConfig(basename: "target")
+        let args = try ColprofArgs.build(config: config)
+        #expect(!args.contains("-u"))
+    }
+}

Tests/ICCeryCoreTests/ColprofProgressTests.swift

@@ -0,0 +1,24 @@
+import Foundation
+import Testing
+@testable import ICCeryCore
+
+@Suite("ColprofProgress")
+struct ColprofProgressTests {
+
+    @Test("Classifies gamut mapping")
+    func gamutMapping() {
+        #expect(ColprofProgressClassifier.classify(line: "Gamut mapping calculation in progress") == .gamutMapping)
+    }
+
+    @Test("Classifies fitting or clut")
+    func fitting() {
+        #expect(ColprofProgressClassifier.classify(line: "Fitting cLUT grid points") == .fittingClut)
+        #expect(ColprofProgressClassifier.classify(line: "clut table") == .fittingClut)
+    }
+
+    @Test("Classifies writing")
+    func writing() {
+        #expect(ColprofProgressClassifier.classify(line: "Writing ICC profile header") == .writingIcc)
+        #expect(ColprofProgressClassifier.classify(line: "icc profile written") == .writingIcc)
+    }
+}

Tests/ICCeryCoreTests/DriftAlertTests.swift

@@ -0,0 +1,105 @@
+import Foundation
+import Testing
+@testable import ICCeryCore
+
+@Suite("DriftAlert")
+struct DriftAlertTests {
+
+    @Test("No alert with fewer than two poor results")
+    func notEnough() {
+        let records = [
+            record(avg: 4.0, at: 1000)
+        ]
+        #expect(DriftAlert.compute(from: records) == nil)
+    }
+
+    @Test("Alert on two poor results one hour apart")
+    func oneHourApart() {
+        let records = [
+            record(avg: 4.0, at: 1000),
+            record(avg: 5.0, at: 4600)
+        ]
+        #expect(DriftAlert.compute(from: records) != nil)
+    }
+
+    @Test("No alert if same day and under one hour")
+    func sameDayUnderHour() {
+        let records = [
+            record(avg: 4.0, at: 1000),
+            record(avg: 5.0, at: 2000)
+        ]
+        #expect(DriftAlert.compute(from: records) == nil)
+    }
+
+    @Test("Alert on distinct days")
+    func distinctDays() {
+        let day1 = record(avg: 4.0, at: 0)
+        let day2 = record(avg: 5.0, at: 86400 + 1000)
+        #expect(DriftAlert.compute(from: [day1, day2]) != nil)
+    }
+
+    @Test("Non-poor records do not trigger")
+    func nonPoor() {
+        let records = [
+            record(avg: 1.0, at: 0),
+            record(avg: 1.5, at: 86400)
+        ]
+        #expect(DriftAlert.compute(from: records) == nil)
+    }
+
+    @Test("Non-poor records break the consecutive poor run")
+    func nonPoorBreaksRun() {
+        let records = [
+            record(avg: 4.0, at: 0),      // poor
+            record(avg: 4.5, at: 86400),  // poor, far apart
+            record(avg: 1.0, at: 90000),  // good — breaks the run
+            record(avg: 4.0, at: 92000)   // poor, recent but close to previous poor
+        ]
+        #expect(DriftAlert.compute(from: records) == nil)
+    }
+
+    @Test("Only the final consecutive poor run is considered")
+    func onlySuffixRun() {
+        let records = [
+            record(avg: 4.0, at: 0),     // poor
+            record(avg: 4.5, at: 18000), // poor, > 1h from first
+            record(avg: 1.0, at: 20000), // good — breaks the run
+            record(avg: 4.0, at: 25000), // poor
+            record(avg: 4.5, at: 26000)  // poor, < 1h and same day
+        ]
+        #expect(DriftAlert.compute(from: records) == nil)
+    }
+
+    @Test("Final consecutive poor run alerts when far apart")
+    func suffixRunAlerts() {
+        let records = [
+            record(avg: 1.0, at: 0),      // good
+            record(avg: 4.0, at: 1000),   // poor
+            record(avg: 4.5, at: 4600)    // poor, 1h after previous
+        ]
+        #expect(DriftAlert.compute(from: records) != nil)
+    }
+
+    @Test("A single final poor record after good records does not alert")
+    func singleFinalPoor() {
+        let records = [
+            record(avg: 1.0, at: 0),
+            record(avg: 4.0, at: 86400)
+        ]
+        #expect(DriftAlert.compute(from: records) == nil)
+    }
+
+    private func record(avg: Double, at offset: TimeInterval) -> VerificationRecord {
+        VerificationRecord(
+            id: "vr-\(Int(offset))",
+            profileName: "p",
+            printerName: "",
+            avgDE: avg,
+            maxDE: avg,
+            rmsDE: avg,
+            patchCount: 1,
+            status: VerificationStatus.from(avgDE: avg),
+            timestamp: Date(timeIntervalSince1970: offset)
+        )
+    }
+}

Tests/ICCeryCoreTests/IccgamutArgsTests.swift

@@ -0,0 +1,16 @@
+import Foundation
+import Testing
+@testable import ICCeryCore
+
+@Suite("IccgamutArgs")
+struct IccgamutArgsTests {
+
+    @Test("Density is 10 and not a directory")
+    func densityNotDirectory() throws {
+        let config = IccgamutConfig(
+            profileURL: URL(fileURLWithPath: "/tmp/MyProfile.icc")
+        )
+        let args = try IccgamutArgs.build(config: config)
+        #expect(args == ["-v", "-d", "10", "/tmp/MyProfile.icc"])
+    }
+}

Tests/ICCeryCoreTests/MeasurementTests.swift

@@ -0,0 +1,296 @@
+import Foundation
+import Testing
+@testable import ICCeryCore
+
+@Suite("InstrumentParser")
+struct InstrumentParserTests {
+
+    @Test("Parses pretty-printed instlist JSON")
+    func json() throws {
+        let json = """
+        {
+          "event": "instruments",
+          "devices": [
+            {"port": 1, "name": "X-Rite i1Pro", "type": "usb"},
+            {"port": 2, "name": "i1Pro 2", "type": "usb"},
+            {"port": 3, "name": "i1iO Table", "type": "usb"}
+          ]
+        }
+        """
+        let devices = try InstrumentParser.parse(json)
+        #expect(devices.count == 3)
+        #expect(devices[0].port == 1)
+        #expect(devices[0].name == "X-Rite i1Pro")
+        #expect(devices[2].port == 3)
+    }
+
+    @Test("Falls back to regex for legacy instlist text")
+    func regexFallback() throws {
+        let text = """
+        1: 'X-Rite i1Pro' on usb
+        2: 'ColorMunki Smile'
+        """ + "\n"
+        let devices = try InstrumentParser.parse(text)
+        #expect(devices.count == 2)
+        #expect(devices[0].port == 1)
+        #expect(devices[1].name == "ColorMunki Smile")
+    }
+
+    @Test("Empty output returns no devices")
+    func empty() throws {
+        #expect(try InstrumentParser.parse("").isEmpty)
+    }
+}
+
+@Suite("ChartreadArgs")
+struct ChartreadArgsTests {
+
+    @Test("Baseline argv and port 1 omits -c")
+    func baseline() throws {
+        let config = ChartreadConfig(basename: "target", selectedPort: 1)
+        let args = try ChartreadArgs.build(config: config)
+        #expect(args == ["-v", "-u", "target"])
+    }
+
+    @Test("Port > 1 emits -c")
+    func portArgument() throws {
+        let config = ChartreadConfig(basename: "target", selectedPort: 3)
+        let args = try ChartreadArgs.build(config: config)
+        #expect(args == ["-v", "-u", "-c", "3", "target"])
+    }
+
+    @Test("LEDs emit -Y l")
+    func leds() throws {
+        let config = ChartreadConfig(
+            basename: "target",
+            selectedPort: 2,
+            enableLEDs: true
+        )
+        let args = try ChartreadArgs.build(config: config)
+        #expect(args.contains("-Y"))
+        #expect(args.contains("l"))
+    }
+
+    @Test("Auto omits -c")
+    func autoPort() throws {
+        let config = ChartreadConfig(basename: "target")
+        let args = try ChartreadArgs.build(config: config)
+        #expect(!args.contains("-c"))
+    }
+}
+
+@Suite("ChartreadClassifier")
+struct ChartreadClassifierTests {
+
+    @Test("Calibration prompt")
+    func calibration() {
+        let r = ChartreadClassifier.classify(
+            line: "Place instrument on calibration tile and hit [Space] to calibrate.",
+            previousState: .idle
+        )
+        #expect(r.state == .calibrating)
+    }
+
+    @Test("Strip awaiting")
+    func awaitingStrip() {
+        let r = ChartreadClassifier.classify(
+            line: "Hit [Space] to read strip A",
+            previousState: .calibrating
+        )
+        #expect(r.state == .awaitingStrip)
+    }
+
+    @Test("Done prompt")
+    func done() {
+        let r = ChartreadClassifier.classify(
+            line: "'d' if/when done",
+            previousState: .awaitingStrip
+        )
+        #expect(r.state == .allStripsRead)
+    }
+
+    @Test("XY place sheet")
+    func placeSheet() {
+        let r = ChartreadClassifier.classify(
+            line: "Please place sheet 1 of 2 on the table",
+            previousState: .idle
+        )
+        #expect(r.state == .tablePlaceSheet)
+        #expect(r.sheetNumber == 1)
+        #expect(r.sheetTotal == 2)
+    }
+
+    @Test("XY locate patch")
+    func locatePatch() {
+        let r = ChartreadClassifier.classify(
+            line: "locate patch A1 with the sight,",
+            previousState: .tablePlaceSheet
+        )
+        #expect(r.state == .tableAlign)
+        #expect(r.alignmentPatch == "A1")
+    }
+
+    @Test("Remove sheet notice preserves state")
+    func removeNotice() {
+        let r = ChartreadClassifier.classify(
+            line: "Please remove last sheet from table",
+            previousState: .tablePlaceSheet
+        )
+        #expect(r.state == .tablePlaceSheet)
+        #expect(r.isRemoveSheetNotice == true)
+    }
+}
+
+@Suite("ChartreadRow")
+struct ChartreadRowTests {
+
+    @Test("Decodes row JSON")
+    func decode() throws {
+        let json = """
+        {"event": "row_complete", "row_id": "A", "row_index": 0, "total_rows": 2,
+         "patch_count": 1, "patches": [
+           {"id": "1", "loc": "A1", "is_pad": false, "device": [0, 50, 100],
+            "expected": {"Lab": [50, 0, 0]},
+            "measured": {"Lab": [51, 1, -1]}}
+         ]}
+        """
+        let row = try JSONDecoder().decode(ChartreadRow.self, from: Data(json.utf8))
+        #expect(row.rowId == "A")
+        #expect(row.patchCount == 1)
+        #expect(row.patches[0].measured.lab?.l == 51)
+    }
+}
+
+@Suite("ColourMath")
+struct ColourMathTests {
+
+    @Test("White XYZ to Lab")
+    func whiteLab() {
+        let white = XYZColor(x: 96.4212, y: 100.0, z: 82.5188)
+        let lab = LabColorMath.xyzToLab(white)
+        #expect(abs(lab.l - 100) < 0.5)
+        #expect(abs(lab.a) < 0.5)
+        #expect(abs(lab.b) < 0.5)
+    }
+
+    @Test("Lab to sRGB roundtrip is clamped")
+    func labToSRGB() {
+        let red = LabColor(l: 55, a: 80, b: 70)
+        let rgb = LabColorMath.labToSRGB(red)
+        #expect(rgb.r > 0.8)
+        #expect(rgb.g < 0.2)
+        #expect(rgb.b < 0.2)
+    }
+
+    @Test("Pad white returns DisplayRGB")
+    func padWhite() {
+        let white = LabColor(l: 95, a: 0, b: 0)
+        let rgb = LabColorMath.labToSRGB(white)
+        #expect(rgb.r > 0.9)
+        #expect(rgb.g > 0.9)
+        #expect(rgb.b > 0.9)
+    }
+
+    @Test("Standard CIEDE2000 vector (Sharma)")
+    func ciede2000() {
+        let a = LabColor(l: 50, a: -1.3802, b: -84.2814)
+        let b = LabColor(l: 50, a: 0.0000, b: -82.7485)
+        #expect(abs(ColorDifference.deltaE00(a, b) - 1.00) < 0.001)
+    }
+
+    @Test("Classification respects thresholds")
+    func classify() {
+        #expect(ColorDifference.classify(deltaE: 0.5, goodMax: 2.0, warningMax: 5.0) == .good)
+        #expect(ColorDifference.classify(deltaE: 3.0, goodMax: 2.0, warningMax: 5.0) == .warning)
+        #expect(ColorDifference.classify(deltaE: 6.0, goodMax: 2.0, warningMax: 5.0) == .bad)
+    }
+}
+
+@Suite("MeasurementArtefacts")
+struct MeasurementArtefactTests {
+
+    private func makeCwd() throws -> URL {
+        let url = FileManager.default.temporaryDirectory
+            .appendingPathComponent(UUID().uuidString)
+        try FileManager.default.createDirectory(at: url, withIntermediateDirectories: true)
+        return url
+    }
+
+    @Test("Discovers passes in order")
+    func discovery() throws {
+        let cwd = try makeCwd()
+        defer { try? FileManager.default.removeItem(at: cwd) }
+
+        try "A".write(to: cwd.appendingPathComponent("target_pass3.ti3"), atomically: true, encoding: .utf8)
+        try "B".write(to: cwd.appendingPathComponent("target_pass1.ti3"), atomically: true, encoding: .utf8)
+        try "C".write(to: cwd.appendingPathComponent("target_pass10.ti3"), atomically: true, encoding: .utf8)
+
+        let passes = MeasurementArtefacts.passSnapshots(basename: "target", cwd: cwd)
+        #expect(passes.map(\.lastPathComponent) == ["target_pass1.ti3", "target_pass3.ti3", "target_pass10.ti3"])
+    }
+
+    @Test("Snapshot and promote are atomic")
+    func snapshotPromote() throws {
+        let cwd = try makeCwd()
+        defer { try? FileManager.default.removeItem(at: cwd) }
+
+        let canonical = cwd.appendingPathComponent("target.ti3")
+        try "canonical".write(to: canonical, atomically: true, encoding: .utf8)
+
+        let pass = try MeasurementArtefacts.snapshotPass(basename: "target", cwd: cwd)
+        #expect(pass.lastPathComponent == "target_pass1.ti3")
+        #expect(!FileManager.default.fileExists(atPath: canonical.path))
+
+        let promoted = try MeasurementArtefacts.promotePass(pass: pass, basename: "target", cwd: cwd)
+        #expect(promoted.lastPathComponent == "target.ti3")
+        #expect(FileManager.default.fileExists(atPath: promoted.path))
+    }
+
+    @Test("Pass collisions handled")
+    func collision() throws {
+        let cwd = try makeCwd()
+        defer { try? FileManager.default.removeItem(at: cwd) }
+
+        let canonical = cwd.appendingPathComponent("target.ti3")
+        try "v1".write(to: canonical, atomically: true, encoding: .utf8)
+        _ = try MeasurementArtefacts.snapshotPass(basename: "target", cwd: cwd)
+
+        try "v2".write(to: canonical, atomically: true, encoding: .utf8)
+        let pass2 = try MeasurementArtefacts.snapshotPass(basename: "target", cwd: cwd)
+        #expect(pass2.lastPathComponent == "target_pass2.ti3")
+    }
+}
+
+@Suite("AverageArgs")
+struct AverageArgsTests {
+
+    @Test("Requires at least two pass files")
+    func passCount() {
+        let cwd = URL(fileURLWithPath: "/tmp")
+        let config = AverageConfig(
+            workingDirectory: cwd,
+            basename: "target",
+            passFiles: [URL(fileURLWithPath: "target_pass1.ti3")]
+        )
+        #expect(throws: AverageArgError.self) {
+            _ = try AverageArgs.build(config: config)
+        }
+    }
+
+    @Test("Output is last and inputs are relative")
+    func ordering() throws {
+        let cwd = URL(fileURLWithPath: "/tmp")
+        let config = AverageConfig(
+            workingDirectory: cwd,
+            basename: "target",
+            passFiles: [
+                URL(fileURLWithPath: "/tmp/target_pass1.ti3"),
+                URL(fileURLWithPath: "/tmp/target_pass2.ti3"),
+            ]
+        )
+        let args = try AverageArgs.build(config: config)
+        #expect(args.first == "-v")
+        #expect(args.last == "target.ti3")
+        #expect(args == ["-v", "target_pass1.ti3", "target_pass2.ti3", "target.ti3"])
+    }
+}

Tests/ICCeryCoreTests/ProfcheckArgsTests.swift

@@ -0,0 +1,17 @@
+import Foundation
+import Testing
+@testable import ICCeryCore
+
+@Suite("ProfcheckArgs")
+struct ProfcheckArgsTests {
+
+    @Test("Hard-coded argv")
+    func argv() throws {
+        let config = ProfcheckConfig(
+            ti3URL: URL(fileURLWithPath: "/tmp/target.ti3"),
+            iccURL: URL(fileURLWithPath: "/tmp/target.icc")
+        )
+        let args = try ProfcheckArgs.build(config: config)
+        #expect(args == ["-v", "-k", "-s", "-u", "/tmp/target.ti3", "/tmp/target.icc"])
+    }
+}

Tests/ICCeryCoreTests/ProfcheckParserTests.swift

@@ -0,0 +1,71 @@
+import Foundation
+import Testing
+@testable import ICCeryCore
+
+@Suite("ProfcheckParser")
+struct ProfcheckParserTests {
+
+    @Test("Prefers JSON report with de2000 keys")
+    func jsonReport() {
+        let output = """
+        No of test patches = 52
+        {"event": "report", "peak_de2000": 2.41, "avg_de2000": 0.85, "rms": 1.02}
+        Profile check complete, errors(CIEDE2000): max. = 9.99, avg. = 9.99, RMS = 9.99
+        """
+        let report = ProfcheckParser.parse(output)
+        #expect(report.isValid == true)
+        #expect(report.patchCount == 52)
+        #expect(report.avgDE == 0.85)
+        #expect(report.maxDE == 2.41)
+        #expect(report.rmsDE == 1.02)
+        #expect(report.status == .excellent)
+    }
+
+    @Test("Falls back to legacy text")
+    func legacyText() {
+        let output = """
+        No of test patches = 120
+        Profile check complete, errors(CIEDE2000): max. = 3.50, avg. = 1.80, RMS = 0.95
+        """
+        let report = ProfcheckParser.parse(output)
+        #expect(report.isValid == true)
+        #expect(report.patchCount == 120)
+        #expect(report.avgDE == 1.80)
+        #expect(report.maxDE == 3.50)
+        #expect(report.rmsDE == 0.95)
+        #expect(report.status == .good)
+    }
+
+    @Test("Broad regex fallback")
+    func regexFallback() {
+        let output = """
+        No of test patches = 10
+        avg = 4.25
+        max = 6.10
+        rms = 2.30
+        """
+        let report = ProfcheckParser.parse(output)
+        #expect(report.isValid == true)
+        #expect(report.avgDE == 4.25)
+        #expect(report.maxDE == 6.10)
+        #expect(report.rmsDE == 2.30)
+        #expect(report.status == .poor)
+    }
+
+    @Test("Unparseable output warns, not zeros")
+    func unparseable() {
+        let output = "some random text without metrics"
+        let report = ProfcheckParser.parse(output)
+        #expect(report.isValid == false)
+        #expect(report.warning != nil)
+        #expect(report.avgDE == nil)
+    }
+
+    @Test("Status bands")
+    func statusBands() {
+        #expect(VerificationStatus.from(avgDE: 0.5) == .excellent)
+        #expect(VerificationStatus.from(avgDE: 1.5) == .good)
+        #expect(VerificationStatus.from(avgDE: 2.5) == .acceptable)
+        #expect(VerificationStatus.from(avgDE: 4.0) == .poor)
+    }
+}

Tests/ICCeryCoreTests/ProfileInstallerTests.swift

@@ -0,0 +1,171 @@
+import Foundation
+import Testing
+@testable import ICCeryCore
+
+/// A `FileManager` subclass that reports a temporary directory as the
+/// user home, so `ProfileInstaller` can be tested without writing to the
+/// real `~/Library/ColorSync/Profiles`.
+private final class TestFileManager: FileManager {
+    let tempHome: URL
+
+    init(home: URL) {
+        self.tempHome = home
+        super.init()
+    }
+
+    override var homeDirectoryForCurrentUser: URL {
+        tempHome
+    }
+}
+
+@Suite("ProfileInstaller")
+struct ProfileInstallerTests {
+
+    private func makeTempDir() throws -> URL {
+        let fm = FileManager.default
+        let tmp = fm.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+        try fm.createDirectory(at: tmp, withIntermediateDirectories: true)
+        return tmp
+    }
+
+    private func makeSource(
+        at dir: URL,
+        name: String,
+        bytes: [UInt8] = Array(repeating: 0, count: 256)
+    ) throws -> URL {
+        let url = dir.appendingPathComponent(name)
+        let data = Data(bytes)
+        try data.write(to: url)
+        return url
+    }
+
+    @Test("Installs .icc to user ColorSync folder")
+    func userInstall() throws {
+        let fm = FileManager.default
+        let tmp = try makeTempDir()
+        let testFM = TestFileManager(home: tmp)
+        let source = try makeSource(at: tmp, name: "test.icc")
+
+        let result = try ProfileInstaller.install(
+            config: InstallProfileConfig(sourceURL: source),
+            fileManager: testFM
+        )
+
+        #expect(result.registered)
+        #expect(!result.overwritten)
+        #expect(!result.renamed)
+        #expect(result.destPath.hasSuffix("test.icc"))
+        #expect(fm.fileExists(atPath: result.destPath))
+    }
+
+    @Test("Overwrite succeeds and replaces the existing file")
+    func overwriteSucceeds() throws {
+        let fm = FileManager.default
+        let tmp = try makeTempDir()
+        let testFM = TestFileManager(home: tmp)
+        let source = try makeSource(at: tmp, name: "m5_profile.icc", bytes: (0..<256).map { UInt8($0) })
+
+        // First install.
+        let first = try ProfileInstaller.install(
+            config: InstallProfileConfig(sourceURL: source),
+            fileManager: testFM
+        )
+        #expect(!first.overwritten)
+
+        // Change the source contents.
+        let newBytes: [UInt8] = (0..<256).map { UInt8(($0 + 100) % 256) }
+        try Data(newBytes).write(to: source)
+
+        let options = InstallProfileOptions(
+            forceOverwrite: true,
+            preferSystem: false,
+            collisionPolicy: .overwrite,
+            openColorPanel: false
+        )
+        let second = try ProfileInstaller.install(
+            config: InstallProfileConfig(sourceURL: source, options: options),
+            fileManager: testFM
+        )
+
+        #expect(second.overwritten)
+        #expect(!second.renamed)
+        #expect(fm.fileExists(atPath: second.destPath))
+        let installed = try Data(contentsOf: URL(fileURLWithPath: second.destPath))
+        #expect(Array(installed) == newBytes)
+    }
+
+    @Test("Preserves .icm source extension")
+    func preservesIcmExtension() throws {
+        let tmp = try makeTempDir()
+        let testFM = TestFileManager(home: tmp)
+        let source = try makeSource(at: tmp, name: "m5_profile.icm")
+
+        let result = try ProfileInstaller.install(
+            config: InstallProfileConfig(sourceURL: source),
+            fileManager: testFM
+        )
+
+        #expect(URL(fileURLWithPath: result.destPath).pathExtension == "icm")
+        #expect(result.destPath.hasSuffix("m5_profile.icm"))
+    }
+
+    @Test("Rejects parent traversal in source path")
+    func rejectsParentTraversal() throws {
+        let fm = FileManager.default
+        let tmp = try makeTempDir()
+
+        // Create a real file in the parent of `tmp` with a path that contains
+        // a literal ".." component.
+        let parent = tmp.deletingLastPathComponent()
+        let naughtyName = "naughty-\(UUID().uuidString).icc"
+        let realFile = parent.appendingPathComponent(naughtyName)
+        _ = try makeSource(at: parent, name: naughtyName)
+        defer { try? fm.removeItem(at: realFile) }
+
+        let sourceURL = tmp
+            .appendingPathComponent("..")
+            .appendingPathComponent(naughtyName)
+        #expect(fm.fileExists(atPath: sourceURL.path))
+
+        do {
+            _ = try ProfileInstaller.install(config: InstallProfileConfig(sourceURL: sourceURL))
+            Issue.record("Expected unsafeStem error")
+        } catch let error as ProfileInstallError {
+            if case .unsafeStem = error { } else { Issue.record("Expected unsafeStem, got \(error)") }
+        } catch {
+            Issue.record("Unexpected error type: \(error)")
+        }
+    }
+
+    @Test("Allows stems with consecutive dots like foo..bar")
+    func allowsDoubleDotStem() throws {
+        let fm = FileManager.default
+        let tmp = try makeTempDir()
+        let testFM = TestFileManager(home: tmp)
+        let source = try makeSource(at: tmp, name: "foo..bar.icc")
+
+        let result = try ProfileInstaller.install(
+            config: InstallProfileConfig(sourceURL: source),
+            fileManager: testFM
+        )
+
+        #expect(result.destPath.hasSuffix("foo..bar.icc"))
+        #expect(fm.fileExists(atPath: result.destPath))
+    }
+
+    @Test("Rejects source files that are too small")
+    func rejectsSmallSource() throws {
+        let tmp = try makeTempDir()
+        let source = tmp.appendingPathComponent("tiny.icc")
+        try Data(repeating: 0, count: 64).write(to: source)
+
+        do {
+            _ = try ProfileInstaller.install(config: InstallProfileConfig(sourceURL: source))
+            Issue.record("Expected sourceTooSmall error")
+        } catch let error as ProfileInstallError {
+            if case .sourceTooSmall = error { } else { Issue.record("Expected sourceTooSmall, got \(error)") }
+        } catch {
+            Issue.record("Unexpected error type: \(error)")
+        }
+    }
+}

Tests/ICCeryCoreTests/VerificationHistoryStoreTests.swift

@@ -0,0 +1,159 @@
+import Foundation
+import Testing
+@testable import ICCeryCore
+
+@Suite("VerificationHistoryStore")
+struct VerificationHistoryStoreTests {
+
+    @Test("Append and cap")
+    func appendAndCap() async throws {
+        let fm = FileManager.default
+        let tmp = fm.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+        try fm.createDirectory(at: tmp, withIntermediateDirectories: true)
+        let url = tmp.appendingPathComponent("verification_history.json")
+
+        let store = VerificationHistoryStore(url: url, capacity: 3)
+        for i in 0..<5 {
+            let record = VerificationRecord(
+                id: "vr-\(i)",
+                profileName: "p",
+                printerName: "",
+                avgDE: Double(i),
+                maxDE: Double(i),
+                rmsDE: Double(i),
+                patchCount: i,
+                status: .good,
+                timestamp: Date(timeIntervalSince1970: TimeInterval(i))
+            )
+            _ = try await store.append(record)
+        }
+
+        let all = await store.all()
+        #expect(all.count == 3)
+        #expect(all.first?.avgDE == 2.0)
+    }
+
+    @Test("Parse failure preserves file")
+    func parseFailurePreservesFile() async {
+        let fm = FileManager.default
+        let tmp = fm.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+        try? fm.createDirectory(at: tmp, withIntermediateDirectories: true)
+        let url = tmp.appendingPathComponent("verification_history.json")
+
+        try? "not json".write(to: url, atomically: true, encoding: .utf8)
+
+        let store = VerificationHistoryStore(url: url)
+        do {
+            _ = try await store.load()
+            Issue.record("load() should throw on invalid JSON")
+        } catch {
+            #expect(fm.fileExists(atPath: url.path))
+        }
+    }
+
+    @Test("Append loads existing records first")
+    func appendLoadsExisting() async throws {
+        let fm = FileManager.default
+        let tmp = fm.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+        try fm.createDirectory(at: tmp, withIntermediateDirectories: true)
+        let url = tmp.appendingPathComponent("verification_history.json")
+
+        // Pre-populate the store on disk.
+        let existing = VerificationRecord(
+            id: "vr-existing",
+            profileName: "p",
+            printerName: "",
+            avgDE: 1.0,
+            maxDE: 1.0,
+            rmsDE: 1.0,
+            patchCount: 1,
+            status: .good,
+            timestamp: Date(timeIntervalSince1970: 0)
+        )
+        let store1 = VerificationHistoryStore(url: url)
+        _ = try await store1.append(existing)
+
+        // A fresh store appending a new record must keep the existing one.
+        let store2 = VerificationHistoryStore(url: url)
+        let new = VerificationRecord(
+            id: "vr-new",
+            profileName: "p",
+            printerName: "",
+            avgDE: 2.0,
+            maxDE: 2.0,
+            rmsDE: 2.0,
+            patchCount: 2,
+            status: .good,
+            timestamp: Date(timeIntervalSince1970: 10)
+        )
+        _ = try await store2.append(new)
+
+        let all = await store2.all()
+        #expect(all.count == 2)
+        #expect(all.contains { $0.id == "vr-existing" })
+        #expect(all.contains { $0.id == "vr-new" })
+    }
+
+    @Test("Append does not overwrite an unparseable file")
+    func appendPreservesUnparseableFile() async {
+        let fm = FileManager.default
+        let tmp = fm.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+        try? fm.createDirectory(at: tmp, withIntermediateDirectories: true)
+        let url = tmp.appendingPathComponent("verification_history.json")
+
+        let badJSON = "not json"
+        try? badJSON.write(to: url, atomically: true, encoding: .utf8)
+
+        let store = VerificationHistoryStore(url: url)
+        let record = VerificationRecord(
+            id: "vr-new",
+            profileName: "p",
+            printerName: "",
+            avgDE: 1.0,
+            maxDE: 1.0,
+            rmsDE: 1.0,
+            patchCount: 1,
+            status: .good,
+            timestamp: Date(timeIntervalSince1970: 0)
+        )
+
+        do {
+            _ = try await store.append(record)
+            Issue.record("append() should propagate the load error")
+        } catch {
+            #expect(fm.fileExists(atPath: url.path))
+            if let data = try? Data(contentsOf: url),
+               let contents = String(data: data, encoding: .utf8) {
+                #expect(contents == badJSON)
+            } else {
+                Issue.record("Could not read preserved file")
+            }
+        }
+    }
+
+    @Test("CSV export quoting")
+    func csvQuoting() async throws {
+        let fm = FileManager.default
+        let tmp = fm.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+        try fm.createDirectory(at: tmp, withIntermediateDirectories: true)
+        let url = tmp.appendingPathComponent("verification_history.json")
+
+        let store = VerificationHistoryStore(url: url)
+        let record = VerificationRecord(
+            id: "a,b",
+            profileName: "\"quoted\"",
+            printerName: "",
+            avgDE: 1.0,
+            maxDE: 2.0,
+            rmsDE: 3.0,
+            patchCount: 1,
+            status: .good,
+            timestamp: Date(timeIntervalSince1970: 0)
+        )
+        _ = try await store.append(record)
+
+        let csv = await store.exportCSV()
+        #expect(csv.contains("\"a,b\""))
+        #expect(csv.contains("\"\"quoted\"\""))
+    }
+}

Tests/ICCeryUITests/AboutHelpUITests.swift

@@ -0,0 +1,72 @@
+import XCTest
+
+/// About and help chrome UI tests (issue #31).
+@MainActor
+final class AboutHelpUITests: XCTestCase {
+
+    private var app: XCUIApplication!
+
+    override func setUp() async throws {
+        continueAfterFailure = false
+        app = XCUIApplication()
+        app.launchEnvironment = ["ICCERY_UI_TESTING": "1"]
+    }
+
+    override func tearDown() async throws {
+        app?.terminate()
+        app = nil
+    }
+
+    private func element(_ id: String) -> XCUIElement {
+        app.descendants(matching: .any)[id]
+    }
+
+    private func waitFor(_ id: String, timeout: TimeInterval = 10) -> XCUIElement {
+        let deadline = Date().addingTimeInterval(timeout)
+        while Date() < deadline {
+            let el = element(id)
+            if el.exists { return el }
+            RunLoop.current.run(until: Date().addingTimeInterval(0.1))
+        }
+        let el = element(id)
+        XCTAssertTrue(el.exists, "Expected element \(id)")
+        return el
+    }
+
+    func testAboutDialogShowsVersionAndBuildDate() throws {
+        app.launch()
+        app.activate()
+
+        let openAbout = app.buttons["openAboutBtn"]
+        XCTAssertTrue(openAbout.waitForExistence(timeout: 10))
+        openAbout.click()
+
+        _ = waitFor("aboutDialog", timeout: 10)
+        XCTAssertTrue(element("aboutVersion").exists)
+        XCTAssertTrue(element("aboutBuildDate").exists)
+
+        let close = app.buttons["closeAboutBtn"]
+        XCTAssertTrue(close.exists)
+        close.click()
+
+        XCTAssertFalse(element("aboutDialog").exists)
+    }
+
+    func testHelpOverlaysDoNotChangeSidebarHeight() throws {
+        app.launch()
+        app.activate()
+
+        let toggle = app.buttons["btnToggleAllHelp"]
+        XCTAssertTrue(toggle.waitForExistence(timeout: 10))
+
+        let sidebar = app.groups.containing(.button, identifier: "openSettingsBtn").element
+        let before = sidebar.frame
+
+        toggle.click()
+        let after = sidebar.frame
+
+        XCTAssertEqual(before.size.height, after.size.height,
+                       "Toggling global help must not reflow the sidebar height.")
+        XCTAssertTrue(app.descendants(matching: .any)["openSettingsBtn"].exists)
+    }
+}

Tests/ICCeryUITests/Fixtures/bin/applycal

@@ -0,0 +1,18 @@
+#!/bin/sh
+# Mock applycal for Milestone 5 UI tests.
+# Copies the input profile to the optional output path.
+while [ "$#" -gt 0 ]; do
+  case "$1" in
+    -v|-a|-u) shift ;;
+    *) break ;;
+  esac
+done
+cal="$1"
+input="$2"
+output="$3"
+if [ -n "$output" ]; then
+  cp "$input" "$output"
+else
+  cp "$cal" "$input.cal.ctl"
+fi
+exit 0

Tests/ICCeryUITests/Fixtures/bin/average

@@ -0,0 +1,35 @@
+#!/bin/sh
+# Mock average for Milestone4UITests.
+# Usage: average -v pass1.ti3 pass2.ti3 ... output.ti3
+# The canonical output is the last argument.
+# Set MOCK_AVERAGE_FAIL=1 to exit with code 1.
+if [ "${MOCK_AVERAGE_FAIL:-0}" -ne 0 ]; then
+  echo "average: could not converge" >&2
+  exit 1
+fi
+
+# Drop leading -v
+shift
+
+output="$1"
+if [ $# -ge 2 ]; then
+  output="$2"
+fi
+
+# Find last argument
+for arg in "$@"; do
+  output="$arg"
+done
+
+# Sanity: the output is the last argument.
+# Write a fake canonical .ti3 that identifies the inputs.
+{
+  echo "CTI3"
+  echo "INPUTS:"
+  for arg in "$@"; do
+    if [ "$arg" != "$output" ]; then
+      echo "$arg"
+    fi
+  done
+} > "$output"
+exit 0

Tests/ICCeryUITests/Fixtures/bin/chartread

@@ -0,0 +1,131 @@
+#!/usr/bin/env python3
+"""Mock chartread for Milestone4UITests.
+
+Supports handheld (MOCK_CHARTREAD_MODE=strip) and XY (MOCK_CHARTREAD_MODE=xy).
+Writes basename.ti3 on receiving 'd' and exits 0.
+Exit 0 and no .ti3 on 'q' before done.
+Usage: chartread -v -u [-c port] [-Y l] basename
+"""
+import json
+import os
+import sys
+
+
+def read_line():
+    try:
+        return sys.stdin.readline()
+    except Exception:
+        return ""
+
+
+def emit_row(payload: dict):
+    text = "ROW_COLORS_JSON: " + json.dumps(payload)
+    print(text, flush=True)
+
+
+def write_ti3(basename: str):
+    if basename:
+        with open(f"{basename}.ti3", "w") as f:
+            f.write("MOCK_TI3\n")
+
+
+def main():
+    mode = os.environ.get("MOCK_CHARTREAD_MODE", "strip")
+    basename = ""
+    for arg in sys.argv[1:]:
+        if arg.startswith("-"):
+            continue
+        basename = arg
+
+    def read_input():
+        line = read_line()
+        if line == "":
+            sys.exit(1)
+        return line.strip()
+
+    if mode == "xy":
+        print("Place instrument on calibration tile and hit [Space] to calibrate.", flush=True)
+        read_input()
+        print("Calibration successful.", flush=True)
+
+        print("Please place sheet 1 of 1 on the table", flush=True)
+        print("hit return to continue, Esc or 'q' to give up", flush=True)
+        read_input()
+
+        print("locate patch A1 with the sight,", flush=True)
+        print("then hit return to continue", flush=True)
+        read_input()
+
+        print("Reading sheet 1...", flush=True)
+        emit_row({
+            "event": "row_complete",
+            "row_id": "A",
+            "row_index": 0,
+            "total_rows": 1,
+            "patch_count": 3,
+            "patches": [
+                {"id": "1", "loc": "A1", "is_pad": False, "device": [0.0, 50.0, 100.0], "expected": {"XYZ": [18.4210, 20.1234, 15.6789], "Lab": [51.98, -8.45, 12.32]}, "measured": {"XYZ": [18.5120, 20.0451, 15.7100], "Lab": [51.89, -8.31, 12.15]}},
+                {"id": "2", "loc": "A2", "is_pad": False, "device": [10.0, 60.0, 90.0], "expected": {"Lab": [60.0, 10.0, -20.0]}, "measured": {"Lab": [60.1, 10.5, -19.5]}},
+                {"id": "3", "loc": "A3", "is_pad": True, "device": [100.0, 100.0, 100.0], "measured": {"Lab": [95.0, 0.0, 0.0]}},
+            ]
+        })
+
+        print("Sheet 1 of 1 read OK", flush=True)
+        print("Please remove last sheet from table", flush=True)
+        print("'d' if/when done", flush=True)
+        while True:
+            line = read_input()
+            if line.startswith("d"):
+                write_ti3(basename)
+                sys.exit(0)
+            if line.startswith("q"):
+                sys.exit(0)
+
+    # Handheld / strip mode (default)
+    print("Place instrument on calibration tile and hit [Space] to calibrate.", flush=True)
+    read_input()
+    print("Calibration successful.", flush=True)
+
+    print("Hit [Space] to read strip A", flush=True)
+    read_input()
+    print("Reading strip A...", flush=True)
+    emit_row({
+        "event": "row_complete",
+        "row_id": "A",
+        "row_index": 0,
+        "total_rows": 2,
+        "patch_count": 3,
+        "patches": [
+            {"id": "1", "loc": "A1", "is_pad": False, "device": [0.0, 50.0, 100.0], "expected": {"XYZ": [18.4210, 20.1234, 15.6789], "Lab": [51.98, -8.45, 12.32]}, "measured": {"XYZ": [18.5120, 20.0451, 15.7100], "Lab": [51.89, -8.31, 12.15]}},
+            {"id": "2", "loc": "A2", "is_pad": False, "device": [10.0, 60.0, 90.0], "expected": {"Lab": [60.0, 10.0, -20.0]}, "measured": {"Lab": [60.1, 10.5, -19.5]}},
+            {"id": "3", "loc": "A3", "is_pad": True, "device": [100.0, 100.0, 100.0], "measured": {"Lab": [95.0, 0.0, 0.0]}},
+        ]
+    })
+
+    print("Hit [Space] to read strip B", flush=True)
+    read_input()
+    print("Reading strip B...", flush=True)
+    emit_row({
+        "event": "row_complete",
+        "row_id": "B",
+        "row_index": 1,
+        "total_rows": 2,
+        "patch_count": 2,
+        "patches": [
+            {"id": "4", "loc": "B1", "is_pad": False, "device": [100.0, 0.0, 0.0], "expected": {"Lab": [40.0, 40.0, 40.0]}, "measured": {"Lab": [38.0, 41.0, 39.0]}},
+            {"id": "5", "loc": "B2", "is_pad": False, "device": [0.0, 100.0, 0.0], "expected": {"Lab": [80.0, -50.0, 50.0]}, "measured": {"Lab": [79.0, -49.0, 51.0]}},
+        ]
+    })
+
+    print("'d' if/when done", flush=True)
+    while True:
+        line = read_input()
+        if line.startswith("d"):
+            write_ti3(basename)
+            sys.exit(0)
+        if line.startswith("q"):
+            sys.exit(0)
+
+
+if __name__ == "__main__":
+    main()

Tests/ICCeryUITests/Fixtures/bin/colprof

@@ -0,0 +1,14 @@
+#!/bin/sh
+# Mock colprof for Milestone 5 UI tests.
+# Writes {basename}.icc next to the last argument and emits progress.
+last=""
+for arg in "$@"; do last="$arg"; done
+if [ "${ICCERY_MOCK_COLPROF_EXIT:-0}" -ne 0 ]; then
+  echo "mock colprof failure" >&2
+  exit "$ICCERY_MOCK_COLPROF_EXIT"
+fi
+echo "Gamut mapping calculation..."
+echo "Fitting cLUT grid points..."
+echo "Writing ICC profile..."
+touch "$last.icc"
+exit 0

Tests/ICCeryUITests/Fixtures/bin/iccgamut

@@ -0,0 +1,13 @@
+#!/bin/sh
+# Mock iccgamut for Milestone 5 UI tests.
+# Writes {stem}.gam next to the profile path.
+last=""
+for arg in "$@"; do last="$arg"; done
+if [ "${ICCERY_MOCK_ICCGAMUT_EXIT:-0}" -ne 0 ]; then
+  echo "mock iccgamut failure" >&2
+  exit "$ICCERY_MOCK_ICCGAMUT_EXIT"
+fi
+stem=$(basename "$last" | sed 's/\.icc$//; s/\.icm$//')
+dir=$(dirname "$last")
+touch "$dir/$stem.gam"
+exit 0

Tests/ICCeryUITests/Fixtures/bin/instlist

@@ -0,0 +1,17 @@
+#!/bin/sh
+# Mock instlist for Milestone4UITests. Emits a pretty JSON device list.
+# Override the list with ICCERY_MOCK_INSTLIST_JSON.
+if [ -n "${ICCERY_MOCK_INSTLIST_JSON}" ]; then
+  echo "${ICCERY_MOCK_INSTLIST_JSON}"
+  exit 0
+fi
+printf '{
+  "event": "instruments",
+  "devices": [
+    {"port": 1, "name": "X-Rite i1Pro", "type": "usb"},
+    {"port": 2, "name": "X-Rite i1Pro 2", "type": "usb"},
+    {"port": 3, "name": "i1iO Table", "type": "usb"}
+  ]
+}
+'
+exit 0

Tests/ICCeryUITests/Fixtures/bin/profcheck

@@ -0,0 +1,12 @@
+#!/bin/sh
+# Mock profcheck for Milestone 5 UI tests.
+# Emits a JSON report and legacy text summary.
+if [ "${ICCERY_MOCK_PROFCHECK_EXIT:-0}" -ne 0 ]; then
+  echo "mock profcheck failure" >&2
+  exit "$ICCERY_MOCK_PROFCHECK_EXIT"
+fi
+echo "No of test patches = 52"
+sleep 0.1
+printf '{"event": "report", "peak_de2000": 2.41, "avg_de2000": 0.85, "rms": 1.02}\n'
+echo "Profile check complete, errors(CIEDE2000): max. = 2.41, avg. = 0.85, RMS = 1.02"
+exit 0

Tests/ICCeryUITests/Milestone2UITests.swift

@@ -164,10 +164,11 @@ final class Milestone2UITests: XCTestCase {
         XCTAssertTrue(FileManager.default.fileExists(
             atPath: workDir.appendingPathComponent("mytarget.ti2").path))
 
-        // M3 stubs: visible but inert.
+        // Print panel is live from M3; a default printer is selected
+        // so both the all-pages and per-page print buttons are enabled.
         XCTAssertTrue(element("rawPrintPanel").exists)
-        XCTAssertFalse(app.buttons["btnPrintAll"].isEnabled)
-        XCTAssertFalse(app.buttons["btnPrintPage-0"].isEnabled)
+        XCTAssertTrue(app.buttons["btnPrintAll"].isEnabled)
+        XCTAssertTrue(app.buttons["btnPrintPage-0"].isEnabled)
         XCTAssertTrue(app.buttons["btnAdvanceToStage3"].isEnabled)
     }
 

Tests/ICCeryUITests/Milestone3UITests.swift

@@ -49,6 +49,23 @@ final class Milestone3UITests: XCTestCase {
         testRoot = nil
     }
 
+    private func waitForFileContent(
+        _ url: URL,
+        containing needle: String,
+        timeout: TimeInterval = 10
+    ) -> String? {
+        let deadline = Date().addingTimeInterval(timeout)
+        while Date() < deadline {
+            if let data = try? Data(contentsOf: url),
+               let text = String(data: data, encoding: .utf8),
+               text.contains(needle) {
+                return text
+            }
+            RunLoop.current.run(until: Date().addingTimeInterval(0.1))
+        }
+        return (try? String(contentsOf: url, encoding: .utf8)) ?? ""
+    }
+
     private func launchApp() {
         app.launch()
         app.activate()
@@ -171,6 +188,14 @@ final class Milestone3UITests: XCTestCase {
         reachPrintPanel()
         _ = waitFor("printerStatusBadge")
 
+        // Wait for the async printer enumeration to select a queue; once
+        // `btnPrintAll` is enabled, `btnPrintPage-0` is too.
+        let deadline = Date().addingTimeInterval(15)
+        while Date() < deadline, !app.buttons["btnPrintAll"].isEnabled {
+            RunLoop.current.run(until: Date().addingTimeInterval(0.1))
+        }
+        XCTAssertTrue(app.buttons["btnPrintAll"].isEnabled)
+
         app.buttons["btnPrintPage-0"].click()
         let argv = waitForLpLine()
         XCTAssertTrue(argv.contains("AP_ColorMatchingMode"), argv)
@@ -202,18 +227,11 @@ final class Milestone3UITests: XCTestCase {
         let stateURL = testRoot
             .appendingPathComponent("AppData")
             .appendingPathComponent("wizard_state.json")
-        XCTAssertTrue(waitForFile(stateURL))
-        let data = try Data(contentsOf: stateURL)
-        let state = String(data: data, encoding: .utf8) ?? ""
-        XCTAssertTrue(state.contains("Mock_Epson_7450"), state)
+        let state = waitForFileContent(
+            stateURL, containing: "Mock_Epson_7450", timeout: 15)
+        XCTAssertNotNil(state)
+        XCTAssertTrue((state ?? "").contains("Mock_Epson_7450"))
     }
 
-    private func waitForFile(_ url: URL, timeout: TimeInterval = 10) -> Bool {
-        let deadline = Date().addingTimeInterval(timeout)
-        while Date() < deadline {
-            if FileManager.default.fileExists(atPath: url.path) { return true }
-            RunLoop.current.run(until: Date().addingTimeInterval(0.1))
-        }
-        return false
-    }
+
 }

Tests/ICCeryUITests/Milestone4UITests.swift

@@ -0,0 +1,143 @@
+import XCTest
+
+/// Milestone 4 UI tests — issues #18–#22.
+/// Uses the same isolated-fixture strategy as M2/M3.
+@MainActor
+final class Milestone4UITests: XCTestCase {
+
+    private var app: XCUIApplication!
+    private var testRoot: URL!
+    private var binDir: URL!
+    private var workDir: URL!
+
+    override func setUp() async throws {
+        continueAfterFailure = false
+        testRoot = FileManager.default.temporaryDirectory
+            .appendingPathComponent("iccery-ui-\(UUID().uuidString)")
+        binDir = URL(fileURLWithPath: #filePath)
+            .deletingLastPathComponent()
+            .appendingPathComponent("Fixtures/bin")
+        workDir = testRoot.appendingPathComponent("work")
+        try FileManager.default.createDirectory(
+            at: workDir, withIntermediateDirectories: true)
+
+        app = XCUIApplication()
+        app.launchEnvironment = [
+            "ICCERY_UI_TESTING": "1",
+            "ICCERY_TEST_ROOT": testRoot.path,
+            "ICCERY_ARGYLL_BINARY_DIR": binDir.path,
+            "ICCERY_TEST_SAVE_TARGET":
+                workDir.appendingPathComponent("mytarget.ti1").path,
+            "ICCERY_TEST_WORKDIR": workDir.path,
+        ]
+    }
+
+    override func tearDown() async throws {
+        app?.terminate()
+        app = nil
+        if let testRoot {
+            try? FileManager.default.removeItem(at: testRoot)
+        }
+        testRoot = nil
+    }
+
+    private func launchApp() {
+        app.launch()
+        app.activate()
+    }
+
+    private func element(_ id: String) -> XCUIElement {
+        app.descendants(matching: .any)[id]
+    }
+
+    private func waitFor(_ id: String, timeout: TimeInterval = 10) -> XCUIElement {
+        let deadline = Date().addingTimeInterval(timeout)
+        while Date() < deadline {
+            let el = element(id)
+            if el.exists { return el }
+            RunLoop.current.run(until: Date().addingTimeInterval(0.1))
+        }
+        let el = element(id)
+        XCTAssertTrue(el.exists, "Expected element \(id)")
+        return el
+    }
+
+    /// Reach Stage 3 by generating a target, creating a layout, and
+    /// advancing from Stage 2.
+    private func reachStage3() {
+        launchApp()
+        app.buttons["btnBrowse"].click()
+        app.buttons["btnGenerate"].click()
+        _ = waitFor("btnCreateLayout", timeout: 20)
+        app.buttons["btnCreateLayout"].click()
+        _ = waitFor("galleryPage-0", timeout: 20)
+        _ = waitFor("btnAdvanceToStage3", timeout: 10)
+        app.buttons["btnAdvanceToStage3"].click()
+        _ = waitFor("stage3TargetBasename", timeout: 10)
+    }
+
+    /// Fixture-driven instrument detection populates the picker.
+    func testInstrumentDetectionPopulatesPicker() throws {
+        reachStage3()
+        app.buttons["btnDetectInstruments"].click()
+        XCTAssertTrue(waitFor("chartreadInstrumentSelect", timeout: 20).exists)
+
+        let picker = app.popUpButtons["chartreadInstrumentSelect"]
+        XCTAssertTrue(picker.waitForExistence(timeout: 5))
+        picker.click()
+
+        // The fixture provides three devices plus the default Auto entry.
+        XCTAssertTrue(app.menuItems.count >= 3)
+    }
+
+    /// End-to-end handheld chartread with the mock fixture produces a
+    /// canonical .ti3 and unlocks Stage 4.
+    func testHandheldFixtureChartreadAndAverage() throws {
+        reachStage3()
+
+        app.buttons["btnDetectInstruments"].click()
+        _ = waitFor("chartreadInstrumentSelect", timeout: 20)
+
+        // Keep Auto (port 1) and start the session.
+        XCTAssertTrue(app.buttons["btnStartRead"].waitForExistence(timeout: 5))
+        app.buttons["btnStartRead"].click()
+
+        // Calibrate.
+        let calibrate = element("btnCalibrate")
+        if !calibrate.waitForExistence(timeout: 25) {
+            let error = element("chartreadLastError").label
+            let value = element("chartreadLastError").value as? String ?? "<nil>"
+            XCTFail("No calibrate button. lastError.label='\(error)' value='\(value)'")
+        }
+        app.buttons["btnCalibrate"].click()
+
+        // Trigger strip A.
+        _ = waitFor("btnTrigger", timeout: 20)
+        app.buttons["btnTrigger"].click()
+
+        // Trigger strip B.
+        _ = waitFor("btnTrigger", timeout: 20)
+        app.buttons["btnTrigger"].click()
+
+        // All strips read → Done & Save appears.
+        _ = waitFor("btnDoneRead", timeout: 20)
+        app.buttons["btnDoneRead"].firstMatch.click()
+
+        // Averaging panel appears with one pass snapshot.
+        _ = waitFor("chartreadAveragingPanel", timeout: 20)
+        _ = waitFor("passCounterBadge", timeout: 20)
+        XCTAssertTrue(app.buttons["btnFinishAndAverage"].waitForExistence(timeout: 5))
+        XCTAssertTrue(app.buttons["btnFinishAndAverage"].isEnabled)
+
+        app.buttons["btnFinishAndAverage"].click()
+
+        // Finish promotion should create the canonical .ti3 and
+        // advance the wizard to Stage 4.
+        let ti3 = workDir.appendingPathComponent("mytarget.ti3")
+        let deadline = Date().addingTimeInterval(20)
+        while Date() < deadline, !FileManager.default.fileExists(atPath: ti3.path) {
+            RunLoop.current.run(until: Date().addingTimeInterval(0.2))
+        }
+        XCTAssertTrue(FileManager.default.fileExists(atPath: ti3.path))
+    }
+}

Tests/ICCeryUITests/Milestone5UITests.swift

@@ -0,0 +1,112 @@
+import Foundation
+import XCTest
+
+/// Milestone 5 UI tests — issues #23–#27.
+@MainActor
+final class Milestone5UITests: XCTestCase {
+
+    private var app: XCUIApplication!
+    private var testRoot: URL!
+    private var binDir: URL!
+    private var workDir: URL!
+    private var appDataDir: URL!
+
+    override func setUp() async throws {
+        continueAfterFailure = false
+        testRoot = FileManager.default.temporaryDirectory
+            .appendingPathComponent("iccery-ui-m5-\(UUID().uuidString)")
+        binDir = URL(fileURLWithPath: #filePath)
+            .deletingLastPathComponent()
+            .appendingPathComponent("Fixtures/bin")
+        workDir = testRoot.appendingPathComponent("work")
+        appDataDir = testRoot.appendingPathComponent("AppData")
+
+        try FileManager.default.createDirectory(
+            at: workDir, withIntermediateDirectories: true)
+        try FileManager.default.createDirectory(
+            at: appDataDir, withIntermediateDirectories: true)
+
+        // Pre-stage a measured .ti3 so the wizard is already on Stage 4.
+        FileManager.default.createFile(
+            atPath: workDir.appendingPathComponent("mytarget.ti3").path,
+            contents: Data("MOCK_TI3".utf8),
+            attributes: nil)
+
+        let state: [String: Any] = [
+            "currentStage": 4,
+            "basename": "mytarget",
+            "cwd": workDir.path,
+            "printerName": "MockPrinter",
+            "sessionMode": "profile"
+        ]
+        let stateData = try JSONSerialization.data(withJSONObject: state, options: [])
+        try stateData.write(to: appDataDir.appendingPathComponent("wizard_state.json"))
+
+        app = XCUIApplication()
+        app.launchEnvironment = [
+            "ICCERY_UI_TESTING": "1",
+            "ICCERY_TEST_ROOT": testRoot.path,
+            "ICCERY_ARGYLL_BINARY_DIR": binDir.path,
+            "ICCERY_TEST_WORKDIR": workDir.path,
+        ]
+    }
+
+    override func tearDown() async throws {
+        app?.terminate()
+        app = nil
+        if let testRoot {
+            try? FileManager.default.removeItem(at: testRoot)
+        }
+        testRoot = nil
+    }
+
+    private func launchApp() {
+        app.launch()
+        if !app.wait(for: .runningForeground, timeout: 10) {
+            app.activate()
+        }
+    }
+
+    private func element(_ id: String) -> XCUIElement {
+        app.descendants(matching: .any)[id]
+    }
+
+    private func waitFor(_ id: String, timeout: TimeInterval = 20) -> XCUIElement {
+        let deadline = Date().addingTimeInterval(timeout)
+        while Date() < deadline {
+            let el = element(id)
+            if el.exists { return el }
+            RunLoop.current.run(until: Date().addingTimeInterval(0.1))
+        }
+        let el = element(id)
+        XCTAssertTrue(el.exists, "Expected element \(id)")
+        return el
+    }
+
+    /// Mock colprof produces a profile, unlocks Stage 5, and the
+    /// mock profcheck reports Good.
+    func testBuildProfileAndVerify() throws {
+        launchApp()
+
+        let create = waitFor("btnCreateProfile")
+        XCTAssertTrue(create.isEnabled)
+        create.click()
+
+        _ = waitFor("btnVerifyProfile", timeout: 30)
+
+        // The mock iccgamut should have written a .gam next to the profile.
+        let gam = workDir.appendingPathComponent("mytarget.gam")
+        let icc = workDir.appendingPathComponent("mytarget.icc")
+        XCTAssertTrue(FileManager.default.fileExists(atPath: icc.path))
+        XCTAssertTrue(FileManager.default.fileExists(atPath: gam.path))
+
+        app.buttons["btnVerifyProfile"].click()
+        _ = waitFor("profcheckStatus", timeout: 30)
+
+        let statusValue = app.staticTexts["profcheckStatus"].firstMatch.value as? String ?? ""
+        XCTAssertTrue(
+            statusValue.contains("Good") || statusValue.contains("Excellent"),
+            "Expected verification status, got '\(statusValue)'"
+        )
+    }
+}

Tests/ICCeryUITests/Milestone6CGATSUITests.swift

@@ -0,0 +1,64 @@
+import Foundation
+import XCTest
+
+/// Milestone 6 CGATS import UI tests (issue #30).
+@MainActor
+final class Milestone6CGATSUITests: XCTestCase {
+
+    private var app: XCUIApplication!
+    private var testRoot: URL!
+    private var datasetURL: URL!
+
+    override func setUp() async throws {
+        continueAfterFailure = false
+
+        testRoot = FileManager.default.temporaryDirectory
+            .appendingPathComponent("iccery-cgats-ui-\(UUID().uuidString)")
+        try FileManager.default.createDirectory(at: testRoot, withIntermediateDirectories: true)
+
+        let csv = """
+        SAMPLE_ID,SAMPLE_LOC,RGB_R,RGB_G,RGB_B,XYZ_X,XYZ_Y,XYZ_Z,LAB_L,LAB_A,LAB_B
+        1,A1,50,0,0,20,10,5,50,60,30
+        2,A2,0,50,0,10,30,5,60,-50,40
+        """
+        datasetURL = testRoot.appendingPathComponent("imported.csv")
+        try csv.write(to: datasetURL, atomically: true, encoding: .utf8)
+
+        app = XCUIApplication()
+        app.launchEnvironment = [
+            "ICCERY_UI_TESTING": "1",
+            "ICCERY_TEST_WORKDIR": testRoot.path,
+            "ICCERY_TEST_DATASET_IMPORT": datasetURL.path
+        ]
+    }
+
+    override func tearDown() async throws {
+        app?.terminate()
+        app = nil
+        if let testRoot {
+            try? FileManager.default.removeItem(at: testRoot)
+        }
+    }
+
+    /// `Milestone6CGATSUITests.importUsesOpenPanelNotSaveTi1`
+    /// Must fail if import presents a save panel or a `.ti1` filter.
+    func testImportUsesOpenPanelNotSaveTi1() throws {
+        app.launch()
+        app.activate()
+
+        XCTAssertTrue(app.buttons["btn-import-dataset"].waitForExistence(timeout: 10))
+        app.buttons["btn-import-dataset"].click()
+
+        // No save panel should appear; the open panel is stubbed under UI testing.
+        let savePanel = app.sheets.firstMatch
+        XCTAssertFalse(savePanel.exists, "Import must use an open panel, never a save panel.")
+
+        // The dataset should be accepted and the user should advance to Stage 4.
+        _ = app.otherElements["stage-4"].waitForExistence(timeout: 10)
+        XCTAssertTrue(app.otherElements["stage-4"].exists)
+
+        // The canonical .ti3 should be written next to the source file.
+        let ti3URL = testRoot.appendingPathComponent("imported.ti3")
+        XCTAssertTrue(FileManager.default.fileExists(atPath: ti3URL.path))
+    }
+}