ProcessManager: spawn / stdin / kill / captured / event bus (#2)

- actor ProcessManager: runStreaming + runCaptured (concurrent pipe
  drain — no 64 KiB deadlock), sendStdin with independent stdin map
  (#84), kill/killAll, duplicate-id rejection (#116)
- Multicast AsyncStream<ProcessEvent> bus: stdout/stderr/exit/error/
  jsonRow (ROW_COLORS_JSON: prefix stripped)
- exit emitted exactly once, gated on both pipes reaching EOF so
  buffered output is never lost on fast exits or kills
- ARGYLL_NOT_INTERACTIVE=1 on every child; argv logged with ~ home
  sanitization; subprocess stdout→info, stderr→warn
- ProcessLineDecoder (byte-split at \n, UTF-8 safe, CRLF, unterminated
  tail flush), JSONAccumulator (multiline JSON for instlist/profcheck/
  manifest), ProcessID conventions
- 19 new tests incl. large-output captured run and stdin round-trip
- Fixup: entitlements gain com.apple.security.device.usb; sidebar
  preset/Calibrate disabled and only Stage 1 enabled per #1 AC

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

Packages/ICCeryCore/Sources/ICCeryCore/Logging/AppLogger.swift

@@ -0,0 +1,55 @@
+import Foundation
+import OSLog
+
+/// Severity levels, matching the v1 `log_level` setting values.
+public enum LogLevel: String, Codable, Sendable, CaseIterable {
+    case error, warn, info, debug, trace
+
+    var osType: OSLogType {
+        switch self {
+        case .error: return .error
+        case .warn:  return .default
+        case .info:  return .info
+        case .debug: return .debug
+        case .trace: return .debug
+        }
+    }
+
+    var rank: Int {
+        switch self {
+        case .error: return 0
+        case .warn:  return 1
+        case .info:  return 2
+        case .debug: return 3
+        case .trace: return 4
+        }
+    }
+}
+
+/// Central logger. For M1 PR2 this writes to `os.Logger` only;
+/// issue #5 adds the rolling file sink and runtime `setLevel`.
+public struct AppLogger: Sendable {
+    public static let shared = AppLogger(category: "app")
+
+    private let osLog: Logger
+    public let category: String
+
+    public init(category: String) {
+        self.category = category
+        self.osLog = Logger(
+            subsystem: AppPaths.bundleIdentifier,
+            category: category
+        )
+    }
+
+    public func log(_ level: LogLevel, _ message: @autoclosure () -> String) {
+        let text = LogSanitizer.sanitize(message())
+        osLog.log(level: level.osType, "\(text, privacy: .public)")
+    }
+
+    public func error(_ message: @autoclosure () -> String) { log(.error, message()) }
+    public func warn(_ message: @autoclosure () -> String) { log(.warn, message()) }
+    public func info(_ message: @autoclosure () -> String) { log(.info, message()) }
+    public func debug(_ message: @autoclosure () -> String) { log(.debug, message()) }
+    public func trace(_ message: @autoclosure () -> String) { log(.trace, message()) }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Logging/LogSanitizer.swift

@@ -0,0 +1,17 @@
+import Foundation
+
+/// Rewrites the user's home directory to `~` in log output
+/// (docs/03 §Logging hygiene — `sanitize_arg_for_logging`).
+public enum LogSanitizer {
+    /// Replaces every occurrence of the current user's home path with `~`.
+    public static func sanitize(_ text: String) -> String {
+        let home = NSHomeDirectory()
+        guard !home.isEmpty else { return text }
+        return text.replacingOccurrences(of: home, with: "~")
+    }
+
+    /// Sanitizes an argv list for display.
+    public static func sanitizeArgs(_ args: [String]) -> String {
+        args.map(sanitize).joined(separator: " ")
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Process/JSONAccumulator.swift

@@ -0,0 +1,59 @@
+import Foundation
+
+/// Accumulates stdout lines into a complete JSON document.
+///
+/// Several Argyll tools (`instlist`, `profcheck`, `printtarg` manifest)
+/// emit pretty-printed multi-line JSON on stdout. Individual lines are
+/// *not* valid JSON — only the whole block is — so callers route stdout
+/// lines here and get `Data` back once the buffer parses.
+///
+/// `ROW_COLORS_JSON: ` lines never reach this type; ProcessManager
+/// diverts them to `jsonRow` events first.
+public struct JSONAccumulator: Sendable {
+    private var buffer = Data()
+
+    public init() {}
+
+    /// Appends one stdout line. Returns the complete document bytes when
+    /// the accumulated buffer forms valid JSON, otherwise `nil`.
+    public mutating func feed(line: String) -> Data? {
+        buffer.append(Data(line.utf8))
+        buffer.append(0x0A)
+        return tryParse()
+    }
+
+    /// Attempts to decode the accumulated buffer; clears it on success.
+    public mutating func decode<T: Decodable>(_ type: T.Type) -> T? {
+        guard let data = tryParse() else { return nil }
+        return try? JSONDecoder().decode(T.self, from: data)
+    }
+
+    /// Raw buffer when it parses, `nil` while still incomplete.
+    public var completeData: Data? {
+        var copy = self
+        return copy.tryParse()
+    }
+
+    public mutating func reset() {
+        buffer.removeAll(keepingCapacity: false)
+    }
+
+    public var isEmpty: Bool { buffer.isEmpty }
+
+    private mutating func tryParse() -> Data? {
+        // Cheap gate: JSON documents start with { or [.
+        guard let first = buffer.first(where: { !$0.isJSONWhitespace }),
+              first == UInt8(ascii: "{") || first == UInt8(ascii: "[")
+        else { return nil }
+        guard (try? JSONSerialization.jsonObject(with: buffer)) != nil else { return nil }
+        let out = buffer
+        buffer.removeAll(keepingCapacity: false)
+        return out
+    }
+}
+
+private extension UInt8 {
+    var isJSONWhitespace: Bool {
+        self == 0x20 || self == 0x09 || self == 0x0A || self == 0x0D
+    }
+}

Packages/ICCeryCore/Sources/ICCeryCore/Process/ProcessEvent.swift

@@ -0,0 +1,36 @@
+import Foundation
+
+/// Events on the process bus — the v2 equivalent of the v1 Tauri events
+/// `process:stdout|stderr|exit|error|json_row` (docs/02 §Event bus).
+public enum ProcessEvent: Sendable, Equatable {
+    /// Non-JSON stdout line. (`process:stdout`)
+    case stdout(id: String, line: String)
+    /// stderr line. (`process:stderr`)
+    case stderr(id: String, line: String)
+    /// Child exited; 0 = success. (`process:exit`)
+    case exit(id: String, code: Int32)
+    /// Spawn failure. (`process:error`)
+    case error(id: String, message: String)
+    /// Stdout line began with `ROW_COLORS_JSON: ` — prefix stripped,
+    /// payload is the remaining raw bytes. (`process:json_row`)
+    case jsonRow(id: String, payload: Data)
+
+    public var id: String {
+        switch self {
+        case .stdout(let id, _), .stderr(let id, _), .exit(let id, _),
+             .error(let id, _), .jsonRow(let id, _):
+            return id
+        }
+    }
+}
+
+public enum ProcessError: Error, Equatable, Sendable {
+    /// A child with this id is still running (#116).
+    case duplicateID(String)
+    /// No child registered under this id.
+    case unknownID(String)
+    /// Process refused to launch.
+    case spawnFailed(String)
+    /// stdin write failed (pipe closed / process gone).
+    case stdinFailed(String)
+}

Packages/ICCeryCore/Sources/ICCeryCore/Process/ProcessID.swift

@@ -0,0 +1,17 @@
+import Foundation
+
+/// Deterministic process ids (docs/02 §Event bus). Listeners must always
+/// filter events on `id` — historical bug #56 was an id mismatch.
+public enum ProcessID {
+    public static let instlist = "instlist"
+
+    public static func targen(_ basename: String) -> String { "targen_\(basename)" }
+    public static func printtarg(_ basename: String) -> String { "printtarg_\(basename)" }
+    public static func chartread(_ basename: String) -> String { "chartread_\(basename)" }
+    public static func average(_ basename: String) -> String { "average_\(basename)" }
+    public static func colprof(_ basename: String) -> String { "colprof_\(basename)" }
+    public static func profcheck(ti3Path: String) -> String { "profcheck_\(ti3Path)" }
+    public static func iccgamut(stem: String) -> String { "iccgamut_\(stem)" }
+    public static func printcal(_ stem: String) -> String { "printcal_\(stem)" }
+    public static func applycal(_ stem: String) -> String { "applycal_\(stem)" }
+}

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

@@ -0,0 +1,41 @@
+import Foundation
+
+/// Incremental byte→line decoder for process pipes.
+///
+/// Splits raw `availableData` chunks at `0x0A`. A newline byte can never
+/// appear inside a multi-byte UTF-8 sequence (continuation bytes are
+/// ≥ 0x80), so splitting bytes at `\n` is always scalar-safe; each line
+/// is then decoded with a lossy fallback for non-UTF-8 output.
+public struct ProcessLineDecoder: Sendable {
+    public private(set) var pending = Data()
+
+    public init() {}
+
+    /// Feeds a chunk; returns every complete line found (without `\n`).
+    public mutating func feed(_ chunk: Data) -> [String] {
+        guard !chunk.isEmpty else { return [] }
+        pending.append(chunk)
+        var lines: [String] = []
+        while let nl = pending.firstIndex(of: 0x0A) {
+            var slice = pending.prefix(upTo: nl)
+            pending = pending.suffix(from: pending.index(after: nl))
+            // Tolerate CRLF output.
+            if slice.last == 0x0D { slice = slice.dropLast() }
+            lines.append(Self.decode(slice))
+        }
+        return lines
+    }
+
+    /// Flushes any unterminated remainder at EOF. Returns `nil` when empty.
+    public mutating func finish() -> String? {
+        guard !pending.isEmpty else { return nil }
+        var rest = pending
+        pending.removeAll(keepingCapacity: false)
+        if rest.last == 0x0D { rest = rest.dropLast() }
+        return rest.isEmpty ? nil : Self.decode(rest)
+    }
+
+    private static func decode(_ bytes: Data.SubSequence) -> String {
+        String(decoding: bytes, as: UTF8.self)
+    }
+}

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

@@ -0,0 +1,354 @@
+import Foundation
+
+/// Captured output from `runCaptured` (used by printcal/applycal —
+/// the only tools whose results arrive as one-shot output).
+public struct CapturedResult: Sendable, Equatable {
+    public let stdout: String
+    public let stderr: String
+    public let exitCode: Int32
+}
+
+/// Spawn / stdin / kill / event bus for Argyll sidecar children
+/// (docs/02 §Event bus, docs/03 §Process manager).
+///
+/// Invariants:
+/// - Duplicate `id` while a child runs is rejected (#116).
+/// - The stdin handle lives in its own map, independent of wait, so
+///   `sendStdin` never blocks on process exit (#84).
+/// - `ARGYLL_NOT_INTERACTIVE=1` is set on every child.
+/// - stdout lines beginning `ROW_COLORS_JSON: ` become `jsonRow` events
+///   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.
+public actor ProcessManager {
+
+    public static let rowColorsPrefix = "ROW_COLORS_JSON: "
+
+    public static let shared = ProcessManager()
+
+    // MARK: - Event bus (multicast)
+
+    private var subscribers: [UUID: AsyncStream<ProcessEvent>.Continuation] = [:]
+
+    /// Subscribe to the event bus. Each call returns an independent
+    /// stream; every event is delivered to every live subscriber.
+    public nonisolated func events() -> AsyncStream<ProcessEvent> {
+        AsyncStream { continuation in
+            let token = UUID()
+            Task { await self.addSubscriber(continuation, token: token) }
+            continuation.onTermination = { _ in
+                Task { await self.removeSubscriber(token) }
+            }
+        }
+    }
+
+    private func addSubscriber(
+        _ continuation: AsyncStream<ProcessEvent>.Continuation,
+        token: UUID
+    ) {
+        subscribers[token] = continuation
+    }
+
+    private func removeSubscriber(_ token: UUID) {
+        subscribers.removeValue(forKey: token)
+    }
+
+    private func emit(_ event: ProcessEvent) {
+        for continuation in subscribers.values {
+            continuation.yield(event)
+        }
+    }
+
+    // MARK: - Child registry
+
+    private struct RunningChild {
+        let process: Process
+        /// stdin lives in its own slot, independent of process wait (#84).
+        var stdin: FileHandle?
+        var stdoutDecoder: ProcessLineDecoder
+        var stderrDecoder: ProcessLineDecoder
+        var stdoutEOF = false
+        var stderrEOF = false
+        /// Set by the termination handler; `exit` is emitted once both
+        /// pipes have also reached EOF.
+        var pendingExitCode: Int32?
+        var finalized = false
+    }
+
+    private var children: [String: RunningChild] = [:]
+    /// Processes owned by `runCaptured` (dup detection + kill support).
+    private var captured: [String: Process] = [:]
+
+    /// Ids of currently-running children.
+    public var runningIDs: [String] { Array(children.keys) + captured.keys }
+
+    public func isRunning(_ id: String) -> Bool {
+        children[id] != nil || captured[id] != nil
+    }
+
+    // MARK: - Spawn (streaming)
+
+    /// Spawns a streaming child. Returns after spawn; callers wait for
+    /// `exit(id:)` events — never assume the return means the tool
+    /// finished (docs/03).
+    public func runStreaming(
+        id: String,
+        binary: URL,
+        arguments: [String],
+        workingDirectory: URL? = nil,
+        environment: [String: String] = [:]
+    ) throws {
+        guard !isRunning(id) else { throw ProcessError.duplicateID(id) }
+
+        let process = Process()
+        let stdinPipe = Pipe()
+        let stdoutPipe = Pipe()
+        let stderrPipe = Pipe()
+        process.executableURL = binary
+        process.arguments = arguments
+        process.currentDirectoryURL = workingDirectory
+        process.standardInput = stdinPipe
+        process.standardOutput = stdoutPipe
+        process.standardError = stderrPipe
+        process.environment = childEnvironment(extra: environment)
+
+        AppLogger(category: "process").debug(
+            "spawn \(id): \(binary.path) \(LogSanitizer.sanitizeArgs(arguments))"
+        )
+
+        children[id] = RunningChild(
+            process: process,
+            stdin: stdinPipe.fileHandleForWriting,
+            stdoutDecoder: ProcessLineDecoder(),
+            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
+            let data = handle.availableData
+            guard let self else { return }
+            Task { await self.ingestOutput(data, id: id, isStderr: false, handle: handle) }
+        }
+        stderrHandle.readabilityHandler = { [weak self] handle in
+            let data = handle.availableData
+            guard let self else { return }
+            Task { await self.ingestOutput(data, id: id, isStderr: true, handle: handle) }
+        }
+
+        process.terminationHandler = { [weak self] proc in
+            guard let self else { return }
+            Task { await self.didTerminate(id: id, code: proc.terminationStatus) }
+        }
+    }
+
+    // MARK: - Spawn (captured)
+
+    /// Runs a child to completion and returns all output. Reads stdout
+    /// and stderr concurrently so a full pipe buffer can never deadlock
+    /// the child. Used by `printcal` / `applycal` (docs/03).
+    public func runCaptured(
+        id: String,
+        binary: URL,
+        arguments: [String],
+        workingDirectory: URL? = nil,
+        environment: [String: String] = [:]
+    ) async throws -> CapturedResult {
+        guard !isRunning(id) else { throw ProcessError.duplicateID(id) }
+
+        let process = Process()
+        let stdoutPipe = Pipe()
+        let stderrPipe = Pipe()
+        process.executableURL = binary
+        process.arguments = arguments
+        process.currentDirectoryURL = workingDirectory
+        process.standardOutput = stdoutPipe
+        process.standardError = stderrPipe
+        process.environment = childEnvironment(extra: environment)
+
+        AppLogger(category: "process").debug(
+            "spawn(captured) \(id): \(binary.path) \(LogSanitizer.sanitizeArgs(arguments))"
+        )
+
+        // Register before run() so a concurrent duplicate spawn fails.
+        captured[id] = process
+
+        do {
+            try process.run()
+        } catch {
+            captured.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
+
+        let code = await withCheckedContinuation { continuation in
+            process.terminationHandler = { proc in
+                continuation.resume(returning: proc.terminationStatus)
+            }
+        }
+
+        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
+
+    /// Writes the exact bytes (caller includes `\n`) to a child's stdin
+    /// and flushes (docs/03 §stdin protocol).
+    public func sendStdin(id: String, bytes: Data) throws {
+        guard let child = children[id] else { throw ProcessError.unknownID(id) }
+        guard let handle = child.stdin else {
+            throw ProcessError.stdinFailed("stdin closed for \(id)")
+        }
+        do {
+            try handle.write(contentsOf: bytes)
+        } catch {
+            throw ProcessError.stdinFailed("\(id): \(error.localizedDescription)")
+        }
+    }
+
+    public func sendStdin(id: String, text: String) throws {
+        try sendStdin(id: id, bytes: Data(text.utf8))
+    }
+
+    // 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) {
+        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) }
+            }
+            return
+        }
+        if let process = captured[id] {
+            if process.isRunning { process.terminate() }
+            if captured.removeValue(forKey: id) != nil {
+                emit(.exit(id: id, code: process.terminationStatus))
+            }
+        }
+    }
+
+    /// 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) }
+        return ids.count
+    }
+
+    // MARK: - Internals
+
+    private func childEnvironment(extra: [String: String]) -> [String: String] {
+        var env = ProcessInfo.processInfo.environment
+        env["ARGYLL_NOT_INTERACTIVE"] = "1"
+        for (key, value) in extra { env[key] = value }
+        return env
+    }
+
+    private func ingestOutput(
+        _ data: Data,
+        id: String,
+        isStderr: Bool,
+        handle: FileHandle
+    ) {
+        guard var child = children[id] else { return }
+
+        if data.isEmpty {
+            // EOF on this pipe.
+            handle.readabilityHandler = nil
+            if isStderr { child.stderrEOF = true } else { child.stdoutEOF = true }
+            children[id] = child
+            maybeFinalize(id: id)
+            return
+        }
+
+        let lines: [String] = isStderr
+            ? child.stderrDecoder.feed(data)
+            : child.stdoutDecoder.feed(data)
+        children[id] = child
+
+        let log = AppLogger(category: "subprocess")
+        for line in lines {
+            if !isStderr, line.hasPrefix(Self.rowColorsPrefix) {
+                let payload = Data(line.dropFirst(Self.rowColorsPrefix.count).utf8)
+                emit(.jsonRow(id: id, payload: payload))
+            } else if isStderr {
+                log.warn("[\(id)] \(line)")
+                emit(.stderr(id: id, line: line))
+            } else {
+                log.info("[\(id)] \(line)")
+                emit(.stdout(id: id, line: line))
+            }
+        }
+    }
+
+    private func didTerminate(id: String, code: Int32) {
+        guard var child = children[id], !child.finalized else { return }
+        child.pendingExitCode = code
+        try? child.stdin?.close()
+        child.stdin = nil
+        children[id] = child
+        maybeFinalize(id: id)
+    }
+
+    /// Emits `exit` once the child has terminated *and* both pipes have
+    /// drained to EOF, so no buffered output is lost.
+    private func maybeFinalize(id: String) {
+        guard var child = children[id],
+              let code = child.pendingExitCode,
+              child.stdoutEOF, child.stderrEOF,
+              !child.finalized
+        else { return }
+        child.finalized = true
+        children.removeValue(forKey: id)
+
+        // Flush unterminated tail lines.
+        if var decoder = Optional(child.stdoutDecoder),
+           let tail = decoder.finish() {
+            if tail.hasPrefix(Self.rowColorsPrefix) {
+                emit(.jsonRow(id: id, payload: Data(tail.dropFirst(Self.rowColorsPrefix.count).utf8)))
+            } else {
+                emit(.stdout(id: id, line: tail))
+            }
+        }
+        if var decoder = Optional(child.stderrDecoder),
+           let tail = decoder.finish() {
+            emit(.stderr(id: id, line: tail))
+        }
+        emit(.exit(id: id, code: code))
+    }
+}

Resources/ICCery.entitlements

@@ -4,5 +4,7 @@
 <dict>
 	<!-- App Sandbox intentionally absent: ICCery must spawn Argyll tools,
 	     read/write user-chosen working directories, and talk to lp/CUPS. -->
+	<key>com.apple.security.device.usb</key>
+	<true/>
 </dict>
 </plist>

Sources/ICCery/SidebarView.swift

@@ -31,21 +31,24 @@ struct SidebarView: View {
 
             Divider().overlay(Theme.border)
 
-            // Preset select (`#presetSelect`). Preset engine lands in #11.
+            // Preset select (`#presetSelect`). Disabled until the preset
+            // engine lands in issue #11.
             Picker("Preset", selection: .constant("none")) {
                 Text("No preset").tag("none")
             }
             .pickerStyle(.menu)
+            .disabled(true)
             .padding(.horizontal, 12)
             .padding(.vertical, 8)
 
-            // Calibrate Printer (`#btnCalibratePrinter`); `#calStatusChip`
-            // is hidden until the calibration library lands in #29.
+            // Calibrate Printer (`#btnCalibratePrinter`). Disabled until
+            // Stage 0 lands in issue #29; `#calStatusChip` likewise.
             Button(action: { model.enterCalibration() }) {
                 Label("Calibrate Printer", systemImage: "slider.horizontal.3")
                     .frame(maxWidth: .infinity)
             }
             .controlSize(.large)
+            .disabled(true)
             .padding(.horizontal, 12)
 
             Divider().overlay(Theme.border)
@@ -56,7 +59,9 @@ struct SidebarView: View {
                 ForEach(WizardStage.stepperStages, id: \.self) { stage in
                     StepperRow(
                         stage: stage,
-                        isActive: model.stage == stage
+                        isActive: model.stage == stage,
+                        // Only Stage 1 until artefact gating lands in #4.
+                        isEnabled: stage == .generate
                     ) {
                         model.go(to: stage)
                     }
@@ -74,6 +79,7 @@ struct SidebarView: View {
 private struct StepperRow: View {
     let stage: WizardStage
     let isActive: Bool
+    let isEnabled: Bool
     let action: () -> Void
 
     var body: some View {
@@ -97,6 +103,8 @@ private struct StepperRow: View {
             .contentShape(Rectangle())
         }
         .buttonStyle(.plain)
+        .disabled(!isEnabled)
+        .opacity(isEnabled ? 1 : 0.45)
         .background(
             RoundedRectangle(cornerRadius: Theme.Metrics.cornerMedium)
                 .fill(isActive ? Theme.accent.opacity(0.15) : .clear)

Tests/ICCeryCoreTests/ProcessManagerTests.swift

@@ -0,0 +1,262 @@
+import Testing
+import Foundation
+@testable import ICCeryCore
+
+/// Helpers shared across ProcessManager tests. Fixture binaries are shell
+/// scripts written to a temp dir — no resource bundling required.
+@Suite("ProcessManager", .serialized)
+struct ProcessManagerTests {
+
+    // MARK: - Fixture plumbing
+
+    private static let fixtureDir: URL = {
+        let dir = FileManager.default.temporaryDirectory
+            .appendingPathComponent("iccery-pm-tests-\(UUID().uuidString)")
+        try! FileManager.default.createDirectory(at: dir, withIntermediateDirectories: true)
+        return dir
+    }()
+
+    /// Writes a shell script fixture and returns its executable URL.
+    private func script(_ name: String, _ body: String) throws -> URL {
+        let url = Self.fixtureDir.appendingPathComponent(name)
+        try body.write(to: url, atomically: true, encoding: .utf8)
+        try FileManager.default.setAttributes(
+            [.posixPermissions: 0o755], ofItemAtPath: url.path
+        )
+        return url
+    }
+
+    /// Collects events for `id` until `.exit`, `timeout` seconds max.
+    private func collect(
+        _ manager: ProcessManager,
+        id: String,
+        timeout: TimeInterval = 10
+    ) async -> [ProcessEvent] {
+        await withCheckedContinuation { cont in
+            let box = Box()
+            Task {
+                for await event in manager.events() {
+                    guard event.id == id else { continue }
+                    box.append(event)
+                    if case .exit = event { break }
+                }
+                if box.finish() { cont.resume(returning: box.events) }
+            }
+            Task {
+                try? await Task.sleep(for: .seconds(timeout))
+                if box.finish() { cont.resume(returning: box.events) }
+            }
+        }
+    }
+
+    private final class Box: @unchecked Sendable {
+        private let lock = NSLock()
+        private var _events: [ProcessEvent] = []
+        private var finished = false
+        var events: [ProcessEvent] { lock.lock(); defer { lock.unlock() }; return _events }
+        func append(_ e: ProcessEvent) { lock.lock(); _events.append(e); lock.unlock() }
+        func finish() -> Bool { lock.lock(); defer { lock.unlock() }; if finished { return false }; finished = true; return true }
+    }
+
+    // MARK: - Tests
+
+    @Test func streamsStdoutAndEmitsExit() async throws {
+        let pm = ProcessManager()
+        let bin = try script("lines.sh", "#!/bin/sh\necho hello\necho world\n")
+        async let events = collect(pm, id: "t1")
+        try await pm.runStreaming(id: "t1", binary: bin, arguments: [])
+        let evs = await events
+        let lines = evs.compactMap { e -> String? in
+            if case .stdout(_, let l) = e { return l }; return nil
+        }
+        #expect(lines == ["hello", "world"])
+        #expect(evs.contains(.exit(id: "t1", code: 0)))
+    }
+
+    @Test func routesStderrSeparately() async throws {
+        let pm = ProcessManager()
+        let bin = try script("err.sh", "#!/bin/sh\necho out\necho oops 1>&2\n")
+        async let evs = collect(pm, id: "t2")
+        try await pm.runStreaming(id: "t2", binary: bin, arguments: [])
+        let events = await evs
+        #expect(events.contains(.stdout(id: "t2", line: "out")))
+        #expect(events.contains(.stderr(id: "t2", line: "oops")))
+    }
+
+    @Test func stripsRowColorsJSONPrefix() async throws {
+        let pm = ProcessManager()
+        let bin = try script(
+            "rows.sh",
+            "#!/bin/sh\necho 'ROW_COLORS_JSON: {\"row\":1}'\necho plain\n"
+        )
+        async let evs = collect(pm, id: "t3")
+        try await pm.runStreaming(id: "t3", binary: bin, arguments: [])
+        let events = await evs
+        let rows = events.compactMap { e -> String? in
+            if case .jsonRow(_, let d) = e { return String(decoding: d, as: UTF8.self) }
+            return nil
+        }
+        #expect(rows == ["{\"row\":1}"])
+        #expect(events.contains(.stdout(id: "t3", line: "plain")))
+        // Prefixed lines must not leak into stdout.
+        #expect(!events.contains(.stdout(id: "t3", line: "ROW_COLORS_JSON: {\"row\":1}")))
+    }
+
+    @Test func unterminatedTailFlushesOnExit() async throws {
+        let pm = ProcessManager()
+        let bin = try script("tail.sh", "#!/bin/sh\nprintf 'no-newline'\n")
+        async let evs = collect(pm, id: "t4")
+        try await pm.runStreaming(id: "t4", binary: bin, arguments: [])
+        #expect(await evs.contains(.stdout(id: "t4", line: "no-newline")))
+    }
+
+    @Test func stdinRoundTrip() async throws {
+        let pm = ProcessManager()
+        // Read two lines then exit naturally — a killed sh would lose its
+        // buffered stdio output, which is exactly the chartread pattern.
+        let bin = try script(
+            "echo.sh",
+            "#!/bin/sh\nIFS= read -r a; echo \"got:$a\"\nIFS= read -r b; echo \"got:$b\"\n"
+        )
+        async let evs = collect(pm, id: "t5")
+        try await pm.runStreaming(id: "t5", binary: bin, arguments: [])
+        try await pm.sendStdin(id: "t5", text: " \n")
+        try await pm.sendStdin(id: "t5", text: "d\n")
+        let events = await evs
+        #expect(events.contains(.stdout(id: "t5", line: "got: ")))
+        #expect(events.contains(.stdout(id: "t5", line: "got:d")))
+    }
+
+    @Test func duplicateIDRejected() async throws {
+        let pm = ProcessManager()
+        let bin = try script("slow.sh", "#!/bin/sh\nsleep 30\n")
+        try await pm.runStreaming(id: "t6", binary: bin, arguments: [])
+        await #expect(throws: ProcessError.duplicateID("t6")) {
+            try await pm.runStreaming(id: "t6", binary: bin, arguments: [])
+        }
+        await pm.kill(id: "t6")
+    }
+
+    @Test func killEmitsExitAndClosesStdin() async throws {
+        let pm = ProcessManager()
+        let bin = try script("slow2.sh", "#!/bin/sh\ncat\n")
+        async let evs = collect(pm, id: "t7")
+        try await pm.runStreaming(id: "t7", binary: bin, arguments: [])
+        await pm.kill(id: "t7")
+        let events = await evs
+        // exit emitted exactly once
+        let exits = events.filter { if case .exit = $0 { return true }; return false }
+        #expect(exits.count == 1)
+        await #expect(throws: ProcessError.unknownID("t7")) {
+            try await pm.sendStdin(id: "t7", text: "d\n")
+        }
+    }
+
+    @Test func killAllCountsSignaled() async throws {
+        let pm = ProcessManager()
+        let bin = try script("slow3.sh", "#!/bin/sh\nsleep 30\n")
+        try await pm.runStreaming(id: "a", binary: bin, arguments: [])
+        try await pm.runStreaming(id: "b", binary: bin, arguments: [])
+        let count = await pm.killAll()
+        #expect(count == 2)
+    }
+
+    @Test func capturedRunReturnsBothStreams() async throws {
+        let pm = ProcessManager()
+        let bin = try script("cap.sh", "#!/bin/sh\necho out-data\necho err-data 1>&2\nexit 3\n")
+        let result = try await pm.runCaptured(id: "cap", binary: bin, arguments: [])
+        #expect(result.stdout.contains("out-data"))
+        #expect(result.stderr.contains("err-data"))
+        #expect(result.exitCode == 3)
+    }
+
+    @Test func capturedRunDoesNotDeadlockOnLargeOutput() async throws {
+        let pm = ProcessManager()
+        // 5000 lines each stream exceeds the 64 KiB pipe buffer.
+        let bin = try script(
+            "big.sh",
+            "#!/bin/sh\ni=0; while [ $i -lt 5000 ]; do echo \"out-$i\"; echo \"err-$i\" 1>&2; i=$((i+1)); done\n"
+        )
+        let result = try await pm.runCaptured(id: "big", binary: bin, arguments: [])
+        #expect(result.stdout.contains("out-4999"))
+        #expect(result.stderr.contains("err-4999"))
+    }
+
+    @Test func argyllEnvVarIsSet() async throws {
+        let pm = ProcessManager()
+        let bin = try script("env.sh", "#!/bin/sh\necho \"ANI=$ARGYLL_NOT_INTERACTIVE\"\n")
+        async let evs = collect(pm, id: "t10")
+        try await pm.runStreaming(id: "t10", binary: bin, arguments: [])
+        #expect(await evs.contains(.stdout(id: "t10", line: "ANI=1")))
+    }
+
+    @Test func unknownIDStdinThrows() async throws {
+        let pm = ProcessManager()
+        await #expect(throws: ProcessError.unknownID("nope")) {
+            try await pm.sendStdin(id: "nope", text: "d\n")
+        }
+    }
+}
+
+@Suite("ProcessLineDecoder")
+struct ProcessLineDecoderTests {
+    @Test func splitsAcrossChunkBoundaries() {
+        var d = ProcessLineDecoder()
+        #expect(d.feed(Data("he".utf8)) == [])
+        #expect(d.feed(Data("llo\nwor".utf8)) == ["hello"])
+        #expect(d.feed(Data("ld\n".utf8)) == ["world"])
+        #expect(d.finish() == nil)
+    }
+
+    @Test func crlfIsStripped() {
+        var d = ProcessLineDecoder()
+        #expect(d.feed(Data("a\r\nb\r\n".utf8)) == ["a", "b"])
+    }
+
+    @Test func finishReturnsRemainder() {
+        var d = ProcessLineDecoder()
+        _ = d.feed(Data("x".utf8))
+        #expect(d.finish() == "x")
+        #expect(d.finish() == nil)
+    }
+}
+
+@Suite("JSONAccumulator")
+struct JSONAccumulatorTests {
+    @Test func multilinePrettyJSON() {
+        var acc = JSONAccumulator()
+        #expect(acc.feed(line: "{") == nil)
+        #expect(acc.feed(line: "  \"k\": 1") == nil)
+        let done = acc.feed(line: "}")
+        #expect(done != nil)
+        let obj = try? JSONSerialization.jsonObject(with: done!) as? [String: Int]
+        #expect(obj?["k"] == 1)
+    }
+
+    @Test func nonJSONLinesIgnored() {
+        var acc = JSONAccumulator()
+        #expect(acc.feed(line: "Reading instrument...") == nil)
+        #expect(acc.feed(line: "still text") == nil)
+        #expect(acc.completeData == nil)
+    }
+
+    @Test func decodeTyped() {
+        struct Doc: Decodable { let n: Int }
+        var acc = JSONAccumulator()
+        // Split so the doc completes on the second feed.
+        #expect(acc.feed(line: "{\"n\":") == nil)
+        let data = acc.feed(line: "7}")
+        #expect(data != nil)
+        let doc = data.flatMap { try? JSONDecoder().decode(Doc.self, from: $0) }
+        #expect(doc?.n == 7)
+        #expect(acc.isEmpty)
+    }
+}
+
+@Suite("LogSanitizer")
+struct LogSanitizerTests {
+    @Test func homeIsRewritten() {
+        let path = "\(NSHomeDirectory())/Documents/foo.ti1"
+        #expect(LogSanitizer.sanitize(path) == "~/Documents/foo.ti1")
+    }
+}