test(m9): replace MainActor.assertIsolated for Swift 5.7 (#115)

MainActor.assertIsolated() requires Swift 5.9 (Xcode 15); the macOS 12
CI runner compiles the test bundle with Swift 5.7 and failed run 31985.
Assert Thread.isMainThread instead — it checks the same contract (the
coalesced log sink hops back to the main actor).

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

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

.gitea/workflows/macos.yml

@@ -24,10 +24,11 @@ jobs:
       - name: Assert Xcode 14 toolchain
         run: xcodebuild -version | grep -E "Xcode 14." || (echo "Unexpected Xcode version" && exit 1)
 
+      # Homebrew's xcodegen formula requires Xcode 15.3, which cannot be
+      # installed on macOS 12 (#109). The script installs a pinned
+      # prebuilt release instead.
       - name: Ensure host tools
-        run: |
+        run: scripts/ensure-host-tools.sh
-          command -v xcodegen || brew install xcodegen
-          python3 -c "import dmgbuild" 2>/dev/null || pip3 install dmgbuild
 
       - name: Generate Xcode project
         run: xcodegen generate --spec project.yml
@@ -134,6 +135,11 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
+      # scripts/package-release.sh runs `xcodegen generate` and dmgbuild;
+      # see build-and-test for why brew is not used on macOS 12 (#109).
+      - name: Ensure host tools
+        run: scripts/ensure-host-tools.sh
+
       - name: Package release
         run: scripts/package-release.sh
         env:

Sources/ICCery/CalibrationView.swift

@@ -3,8 +3,8 @@ import ICCeryCore
 
 /// Stage 0 calibration dashboard (issue #29, docs/07).
 struct CalibrationView: View {
-    @Bindable var model: CalibrationViewModel
+    @ObservedObject var model: CalibrationViewModel
-    @Bindable var wizard: WizardViewModel
+    @ObservedObject var wizard: WizardViewModel
 
     var body: some View {
         VStack(alignment: .leading, spacing: 0) {
@@ -73,7 +73,7 @@ struct CalibrationView: View {
 
                     if let url = model.computedCalURL {
                         Toggle("Apply calibration to next profile", isOn: $model.applyToProfile)
-                            .onChange(of: model.applyToProfile) { model.updateApplyToProfile() }
+                            .onChange(of: model.applyToProfile) { _ in model.updateApplyToProfile() }
                             .accessibilityIdentifier("calApplyToggle")
 
                         Text("Loaded: \(url.lastPathComponent)")
@@ -96,7 +96,6 @@ struct CalibrationView: View {
                     }
                 }
             }
-            .formStyle(.grouped)
 
             HStack {
                 Spacer()

Sources/ICCery/CalibrationViewModel.swift

@@ -1,13 +1,12 @@
+import Combine
 import Foundation
-import Observation
 import SwiftUI
 import ICCeryCore
 
 /// Stage 0 calibration workflow: generate wedge, print, measure, and
 /// compute `.cal` curves.
 @MainActor
-@Observable
+final class CalibrationViewModel: ObservableObject {
-final class CalibrationViewModel {
 
     let workflow: TargetWorkflowViewModel
     let profile: ProfileWorkflowViewModel
@@ -15,16 +14,16 @@ final class CalibrationViewModel {
 
     // MARK: - Form state
 
-    var colourSpace: ColourSpace = .cmyk
+    @Published var colourSpace: ColourSpace = .cmyk
-    var steps: Int = 21
+    @Published var steps: Int = 21
-    var whitePatches: Int = 4
+    @Published var whitePatches: Int = 4
-    var includeNeutralEmphasis: Bool = false
+    @Published var includeNeutralEmphasis: Bool = false
-    var inkLimit: String = "320"
+    @Published var inkLimit: String = "320"
-    var applyToProfile: Bool = false
+    @Published var applyToProfile: Bool = false
-    var computedCalURL: URL?
+    @Published var computedCalURL: URL?
-    var calibrationLog: [String] = []
+    @Published var calibrationLog: [String] = []
-    var isGenerating = false
+    @Published var isGenerating = false
-    var isComputing = false
+    @Published var isComputing = false
 
     init(workflow: TargetWorkflowViewModel, profile: ProfileWorkflowViewModel, environment: AppEnvironment) {
         self.workflow = workflow

Sources/ICCery/GamutView.swift

@@ -69,12 +69,12 @@ internal struct GamutSceneGeometryBuilder {
 /// a* (green-red) axis is horizontal, L* (lightness) is vertical, and b*
 /// (blue-yellow) is depth.
 struct GamutView: View {
-    @State private var viewModel: GamutViewModel
+    @StateObject private var viewModel: GamutViewModel
     @State private var pause: () -> Void = {}
     @FocusState private var isFocused: Bool
 
     init(profileGamURL: URL? = nil) {
-        _viewModel = State(wrappedValue: GamutViewModel(profileGamURL: profileGamURL))
+        _viewModel = StateObject(wrappedValue: GamutViewModel(profileGamURL: profileGamURL))
     }
 
     var body: some View {
@@ -87,11 +87,6 @@ struct GamutView: View {
             )
             .focusable()
             .focused($isFocused)
-            .focusEffectDisabled()
-            .onKeyPress(.init("R"), action: {
-                viewModel.resetCamera()
-                return .handled
-            })
             .onAppear { isFocused = true }
 
             VStack {
@@ -148,6 +143,7 @@ private struct GamutSceneView: NSViewRepresentable {
         context.coordinator.scnView = scnView
         context.coordinator.scene = scene
         context.coordinator.buildScene(profile: profileMesh, reference: referenceMesh)
+        context.coordinator.installKeyMonitor()
 
         return scnView
     }
@@ -168,6 +164,7 @@ private struct GamutSceneView: NSViewRepresentable {
     }
 
     static func dismantleNSView(_ nsView: SCNView, coordinator: Coordinator) {
+        coordinator.removeKeyMonitor()
         nsView.isPlaying = false
     }
 
@@ -175,6 +172,7 @@ private struct GamutSceneView: NSViewRepresentable {
     final class Coordinator: NSObject {
         weak var scnView: SCNView?
         weak var scene: SCNScene?
+        private var keyMonitor: Any?
 
         private let profileNode = SCNNode()
         private let referenceGroup = SCNNode()
@@ -431,6 +429,31 @@ private struct GamutSceneView: NSViewRepresentable {
             scnView?.isPlaying = false
         }
 
+        /// Local key-down monitor for the R camera-reset shortcut (the
+        /// SwiftUI key-press modifier is unavailable on macOS 12). Only
+        /// events aimed at this view's window are handled; everything
+        /// else passes through untouched.
+        func installKeyMonitor() {
+            guard keyMonitor == nil else { return }
+            keyMonitor = NSEvent.addLocalMonitorForEvents(matching: .keyDown) {
+                [weak self] event in
+                guard let self,
+                      let scnView = self.scnView,
+                      event.window === scnView.window,
+                      event.charactersIgnoringModifiers?.uppercased() == "R"
+                else { return event }
+                self.resetCamera()
+                return nil
+            }
+        }
+
+        func removeKeyMonitor() {
+            if let keyMonitor {
+                NSEvent.removeMonitor(keyMonitor)
+                self.keyMonitor = nil
+            }
+        }
+
         func resetCamera() {
             guard let scnView else { return }
 

Sources/ICCery/GamutViewModel.swift

@@ -1,26 +1,25 @@
+import Combine
 import Foundation
 import ICCeryCore
-import Observation
 
 /// View model for the native SceneKit gamut viewer.
 ///
 /// Loads the bundled `sRGB.gam` reference immediately and, optionally, a
 /// printer/profile `.gam` from the current working directory.
 @MainActor
-@Observable
+final class GamutViewModel: ObservableObject {
-final class GamutViewModel {
 
     /// Parsed reference sRGB gamut mesh.
-    var sRGBMesh: GamutMesh?
+    @Published var sRGBMesh: GamutMesh?
 
     /// Parsed printer/profile gamut mesh.
-    var profileMesh: GamutMesh?
+    @Published var profileMesh: GamutMesh?
 
     /// User-facing status line.
-    var status = "Loading gamut…"
+    @Published var status = "Loading gamut…"
 
     /// Closure injected into the SceneKit view to request a camera reset.
-    var resetCamera: () -> Void = {}
+    @Published var resetCamera: () -> Void = {}
 
     private let profileGamURL: URL?
 

Sources/ICCery/ICCeryApp.swift

@@ -5,11 +5,11 @@ import SwiftUI
 @main
 struct ICCeryApp: App {
     @NSApplicationDelegateAdaptor(AppDelegate.self) private var appDelegate
-    @State private var workflow: TargetWorkflowViewModel
+    @StateObject private var workflow: TargetWorkflowViewModel
 
     init() {
         let environment = AppEnvironment.live()
-        _workflow = State(initialValue: TargetWorkflowViewModel(environment: environment))
+        _workflow = StateObject(wrappedValue: TargetWorkflowViewModel(environment: environment))
         try? AppPaths.ensureDirectories()
         // Log level is runtime state — apply persisted settings at
         // startup (#158); the Settings sheet re-applies on save.
@@ -17,15 +17,17 @@ struct ICCeryApp: App {
     }
 
     var body: some Scene {
-        // Single fixed window (docs/21 §Shell: 1280×800, min 1100×700).
+        // Single fixed window (docs/21 §Shell: 1280×800, min 1100×700);
-        Window("ICCery", id: "main") {
+        // metrics are applied by AppDelegate once the window exists.
+        WindowGroup("ICCery") {
             RootView(workflow: workflow)
                 .frame(minWidth: 1100, minHeight: 700)
                 .preferredColorScheme(.dark)
         }
-        .defaultSize(width: 1280, height: 800)
+        .commands {
-        .windowResizability(.contentMinSize)
+            // Single-window app: no File > New window.
-        .defaultPosition(.center)
+            CommandGroup(replacing: .newItem) {}
+        }
     }
 }
 
@@ -37,16 +39,30 @@ final class AppDelegate: NSObject, NSApplicationDelegate {
     private var terminationRequested = false
 
     func applicationDidFinishLaunching(_ notification: Notification) {
-        // SwiftUI `Window` scenes launched by XCTest stay
+        // SwiftUI scenes launched by XCTest stay `.runningBackground`
-        // `.runningBackground` unless the app takes regular activation
+        // unless the app takes regular activation and orders the window
-        // and orders the window front (CI run 29804).
+        // front (CI run 29804).
         NSApp.setActivationPolicy(.regular)
         for window in NSApp.windows {
+            configureMainWindow(window)
             window.makeKeyAndOrderFront(nil)
         }
         NSApp.activate(ignoringOtherApps: true)
     }
 
+    /// docs/21 §Shell: 1280×800 content, min 1100×700, centred.
+    private func configureMainWindow(_ window: NSWindow) {
+        window.setContentSize(NSSize(width: 1280, height: 800))
+        window.contentMinSize = NSSize(width: 1100, height: 700)
+        window.center()
+    }
+
+    /// Dock-click reopen: let the WindowGroup re-show or recreate the
+    /// main window when none are visible.
+    func applicationShouldHandleReopen(_ sender: NSApplication, hasVisibleWindows flag: Bool) -> Bool {
+        true
+    }
+
     func applicationShouldTerminateAfterLastWindowClosed(_ sender: NSApplication) -> Bool {
         true
     }

Sources/ICCery/MeasurementWorkflowViewModel.swift

@@ -1,5 +1,5 @@
+import Combine
 import Foundation
-import Observation
 import SwiftUI
 import ICCeryCore
 
@@ -32,8 +32,7 @@ enum XYStep: Equatable, Sendable {
 
 /// Stage 3 workflow state and interaction (issues #18–#22).
 @MainActor
-@Observable
+final class MeasurementWorkflowViewModel: ObservableObject {
-final class MeasurementWorkflowViewModel {
 
     // MARK: - Authorities
 
@@ -42,37 +41,37 @@ final class MeasurementWorkflowViewModel {
 
     // MARK: - Settings-driven thresholds
 
-    private(set) var goodMax: Double = 2.0
+    @Published private(set) var goodMax: Double = 2.0
-    private(set) var warningMax: Double = 5.0
+    @Published private(set) var warningMax: Double = 5.0
-    private(set) var enableLEDs: Bool = false
+    @Published private(set) var enableLEDs: Bool = false
 
     // MARK: - Instrument detection
 
-    var instruments: [InstrumentDevice] = []
+    @Published var instruments: [InstrumentDevice] = []
-    var selectedInstrument: InstrumentSelection = .auto
+    @Published var selectedInstrument: InstrumentSelection = .auto
-    var isDetecting = false
+    @Published var isDetecting = false
-    var detectionError: String?
+    @Published var detectionError: String?
 
     // MARK: - Chartread session
 
-    var isChartreadRunning = false
+    @Published var isChartreadRunning = false
-    var chartreadState: ChartreadState = .idle
+    @Published var chartreadState: ChartreadState = .idle
-    var currentPrompt: String?
+    @Published var currentPrompt: String?
-    var requestedWarningKey: String?
+    @Published var requestedWarningKey: String?
-    var chartreadLog: [String] = []
+    @Published var chartreadLog: [String] = []
-    var rows: [ChartreadRow] = []
+    @Published var rows: [ChartreadRow] = []
-    var swatchRows: [SwatchRow] = []
+    @Published var swatchRows: [SwatchRow] = []
-    var showRemoveSheetNotice = false
+    @Published var showRemoveSheetNotice = false
     /// Stage-local chartread error notice (`#chartreadLastError`, #80).
-    var chartreadNotice: Notice?
+    @Published var chartreadNotice: Notice?
     private var chartreadTask: Task<Void, Never>?
 
     // MARK: - Averaging
 
-    var passSnapshots: [URL] = []
+    @Published var passSnapshots: [URL] = []
-    var isFinishing = false
+    @Published var isFinishing = false
-    var finishNotice: Notice?
+    @Published var finishNotice: Notice?
-    var resumedFromTi2 = false
+    @Published var resumedFromTi2 = false
 
     init(wizard: WizardViewModel, environment: AppEnvironment) {
         self.wizard = wizard

Sources/ICCery/PresetDialogs.swift

@@ -4,7 +4,7 @@ import ICCeryCore
 /// `#savePresetDialog` — save the live Stage 1/2 form as a custom
 /// preset (issue #11). Names/descriptions render via `Text` only (#114).
 struct SavePresetDialog: View {
-    @Bindable var workflow: TargetWorkflowViewModel
+    @ObservedObject var workflow: TargetWorkflowViewModel
 
     var body: some View {
         VStack(alignment: .leading, spacing: 14) {
@@ -35,7 +35,7 @@ struct SavePresetDialog: View {
 
 /// `#managePresetsDialog` — list, delete (custom only), import, export.
 struct ManagePresetsDialog: View {
-    @Bindable var workflow: TargetWorkflowViewModel
+    @ObservedObject var workflow: TargetWorkflowViewModel
 
     var body: some View {
         VStack(alignment: .leading, spacing: 12) {

Sources/ICCery/Print/PrintSessionViewModel.swift

@@ -1,23 +1,22 @@
+import Combine
 import Foundation
-import Observation
 import ICCeryCore
 
 /// CUPS queue selection, bound print panel, and `lp` spool (issues 12–15, 17 / #85).
 @MainActor
-@Observable
+final class PrintSessionViewModel: ObservableObject {
-final class PrintSessionViewModel {
     let wizard: WizardViewModel
     let environment: AppEnvironment
 
-    var printers: [Printer] = []
+    @Published var printers: [Printer] = []
-    var selectedPrinter = ""
+    @Published var selectedPrinter = ""
-    var printerCaps = PrinterCapabilities()
+    @Published var printerCaps = PrinterCapabilities()
-    var selectedTray: Int?
+    @Published var selectedTray: Int?
-    var selectedMediaType: String?
+    @Published var selectedMediaType: String?
-    var printOrientation = "portrait"
+    @Published var printOrientation = "portrait"
-    var capturedCupsOptions: [String: String] = [:]
+    @Published var capturedCupsOptions: [String: String] = [:]
-    var printNotice: Notice?
+    @Published var printNotice: Notice?
-    var isPrinting = false
+    @Published var isPrinting = false
     private var printTask: Task<Void, Never>?
 
     init(wizard: WizardViewModel, environment: AppEnvironment) {
@@ -111,7 +110,8 @@ final class PrintSessionViewModel {
         isPrinting = true
         let task = Task { @MainActor [weak self] in
             guard let self else { return }
-            defer { self.printTask = nil }
+            // `defer` cannot mutate isolated state under Swift 5.7
+            // (Xcode 14.2 / macOS 12 runner), so clear explicitly (#113).
             var printed = 0
             for page in result.pages {
                 do {
@@ -124,6 +124,7 @@ final class PrintSessionViewModel {
                             + error.localizedDescription
                     )
                     isPrinting = false
+                    self.printTask = nil
                     return
                 }
             }
@@ -133,6 +134,7 @@ final class PrintSessionViewModel {
                 autoHideAfter: nil
             )
             isPrinting = false
+            self.printTask = nil
         }
         printTask = task
     }
@@ -142,7 +144,6 @@ final class PrintSessionViewModel {
         isPrinting = true
         let task = Task { @MainActor [weak self] in
             guard let self else { return }
-            defer { self.printTask = nil }
             do {
                 try await spool(page, index: page.index, pageSize: pageSize)
                 printNotice = Notice(
@@ -157,6 +158,7 @@ final class PrintSessionViewModel {
                 )
             }
             isPrinting = false
+            self.printTask = nil
         }
         printTask = task
     }

Sources/ICCery/ProfileWorkflowViewModel.swift

@@ -1,12 +1,11 @@
+import Combine
 import Foundation
-import Observation
 import SwiftUI
 import ICCeryCore
 
 /// Stage 4/5 workflow: build a profile, verify it, track drift, and install.
 @MainActor
-@Observable
+final class ProfileWorkflowViewModel: ObservableObject {
-final class ProfileWorkflowViewModel {
 
     let wizard: WizardViewModel
     let environment: AppEnvironment
@@ -14,50 +13,50 @@ final class ProfileWorkflowViewModel {
 
     // MARK: - Stage 4 form
 
-    var algorithm: String = "l"      // l | x | X | m
+    @Published var algorithm: String = "l"      // l | x | X | m
-    var quality: String = "m"        // l | m | h | u
+    @Published var quality: String = "m"        // l | m | h | u
-    var intent: String = ""          // usually empty at Stage 4
+    @Published var intent: String = ""          // usually empty at Stage 4
-    var fwaSelection: ColprofFwaSelection = .none
+    @Published var fwaSelection: ColprofFwaSelection = .none
-    var fwaCustomPath: String = ""
+    @Published var fwaCustomPath: String = ""
-    var illuminant: String = ""
+    @Published var illuminant: String = ""
-    var observer: String = ""
+    @Published var observer: String = ""
-    var inputViewingCond: String = ""
+    @Published var inputViewingCond: String = ""
-    var outputViewingCond: String = ""
+    @Published var outputViewingCond: String = ""
-    var profileDescription: String = ""
+    @Published var profileDescription: String = ""
-    var copyright: String = ""
+    @Published var copyright: String = ""
 
     // MARK: - Run state
 
-    var isColprofRunning = false
+    @Published var isColprofRunning = false
-    var colprofLog: [String] = []
+    @Published var colprofLog: [String] = []
-    var colprofProgress: String?
+    @Published var colprofProgress: String?
-    var createdProfileURL: URL?
+    @Published var createdProfileURL: URL?
     /// Path to the `.gam` gamut mesh extracted post-`colprof` (issue #28).
-    var createdGamutURL: URL?
+    @Published var createdGamutURL: URL?
 
     // MARK: - Stage 4/5 calibration (issue #24)
 
-    var applyCalibration = false
+    @Published var applyCalibration = false
-    var calibrationFile: String = ""
+    @Published var calibrationFile: String = ""
 
     // MARK: - Stage 5 verification (issue #25)
 
-    var profcheckReport: ProfcheckReport?
+    @Published var profcheckReport: ProfcheckReport?
-    var profcheckWarning: String?
+    @Published var profcheckWarning: String?
-    var isProfcheckRunning = false
+    @Published var isProfcheckRunning = false
 
     // MARK: - History / drift (issue #26)
 
-    var verificationHistory: [VerificationRecord] = []
+    @Published var verificationHistory: [VerificationRecord] = []
-    var driftPrinterFilter: String? = nil
+    @Published var driftPrinterFilter: String? = nil
-    var driftAlert: String?
+    @Published var driftAlert: String?
-    var isHistoryStoreError: String?
+    @Published var isHistoryStoreError: String?
 
     // MARK: - Install (issue #27)
 
-    var installResult: InstallProfileResult?
+    @Published var installResult: InstallProfileResult?
-    var showingInstallCollision = false
+    @Published var showingInstallCollision = false
-    var installCollisionMessage: String = ""
+    @Published var installCollisionMessage: String = ""
     var pendingInstallOptions: InstallProfileOptions?
 
     init(wizard: WizardViewModel, environment: AppEnvironment) {

Sources/ICCery/RootView.swift

@@ -5,12 +5,18 @@ import ICCeryCore
 /// Root layout: 270 pt sidebar + main stage area with the notification
 /// banner pinned to the top (docs/21 §Shell).
 struct RootView: View {
-    @Bindable var workflow: TargetWorkflowViewModel
+    @ObservedObject var workflow: TargetWorkflowViewModel
+    /// Observed directly: nested ObservableObjects are not tracked
+    /// through the parent's `objectWillChange`.
+    @ObservedObject private var model: WizardViewModel
     @State private var showingSettings = false
     @State private var showingAbout = false
     @State private var showingAllHelp = false
 
-    private var model: WizardViewModel { workflow.wizard }
+    init(workflow: TargetWorkflowViewModel) {
+        self.workflow = workflow
+        self._model = ObservedObject(wrappedValue: workflow.wizard)
+    }
 
     var body: some View {
         HStack(spacing: 0) {
@@ -64,11 +70,11 @@ struct RootView: View {
 }
 
 /// Content for the active wizard stage. Isolated into its own view so that
-/// `WizardViewModel` is tracked via `@Bindable` instead of the parent's
+/// `WizardViewModel` is tracked via `@ObservedObject` instead of the parent's
 /// `TargetWorkflowViewModel`, which does not observe nested `wizard` mutations.
 private struct WizardStageContent: View {
-    @Bindable var model: WizardViewModel
+    @ObservedObject var model: WizardViewModel
-    var workflow: TargetWorkflowViewModel
+    @ObservedObject var workflow: TargetWorkflowViewModel
 
     var body: some View {
         switch model.stage {

Sources/ICCery/SettingsView.swift

@@ -4,7 +4,7 @@ import ICCeryCore
 /// Settings sheet (issue #5, docs/21 §Settings). Dark-theme Form with
 /// the full v1 field set; ΔE validation shows inline under the fields.
 struct SettingsView: View {
-    @State var model = SettingsViewModel()
+    @StateObject var model = SettingsViewModel()
     @Environment(\.dismiss) private var dismiss
 
     private static let instruments: [(code: String, label: String)] = [
@@ -143,7 +143,6 @@ struct SettingsView: View {
                     }
                 }
             }
-            .formStyle(.grouped)
 
             Divider()
 

Sources/ICCery/SettingsViewModel.swift

@@ -1,4 +1,5 @@
 import AppKit
+import Combine
 import Foundation
 import ICCeryCore
 
@@ -6,12 +7,11 @@ import ICCeryCore
 /// validation; the log level is applied live via `LogSink` (#158) and a
 /// `settingsDidChange` notification fans out to #20.
 @MainActor
-@Observable
+final class SettingsViewModel: ObservableObject {
-final class SettingsViewModel {
 
-    var settings: AppSettings
+    @Published var settings: AppSettings
-    var validationErrors: [String] = []
+    @Published var validationErrors: [String] = []
-    var savedFlash = false
+    @Published var savedFlash = false
 
     private let store: SettingsStore
     private let sink: LogSink

Sources/ICCery/SidebarView.swift

@@ -4,12 +4,28 @@ import ICCeryCore
 /// 270 pt sidebar (docs/21 §Shell): logo, settings/about buttons, preset
 /// select, Calibrate Printer + status chip, and the 1–5 stepper.
 struct SidebarView: View {
-    @Bindable var workflow: TargetWorkflowViewModel
+    @ObservedObject var workflow: TargetWorkflowViewModel
+    /// Observed directly: nested ObservableObjects are not tracked
+    /// through the parent's `objectWillChange`.
+    @ObservedObject private var model: WizardViewModel
+    @ObservedObject private var profile: ProfileWorkflowViewModel
     var onOpenSettings: () -> Void
     var onOpenAbout: () -> Void
     @Binding var showingAllHelp: Bool
 
-    private var model: WizardViewModel { workflow.wizard }
+    init(
+        workflow: TargetWorkflowViewModel,
+        onOpenSettings: @escaping () -> Void,
+        onOpenAbout: @escaping () -> Void,
+        showingAllHelp: Binding<Bool>
+    ) {
+        self.workflow = workflow
+        self._model = ObservedObject(wrappedValue: workflow.wizard)
+        self._profile = ObservedObject(wrappedValue: workflow.profile)
+        self.onOpenSettings = onOpenSettings
+        self.onOpenAbout = onOpenAbout
+        self._showingAllHelp = showingAllHelp
+    }
 
     var body: some View {
         VStack(alignment: .leading, spacing: 0) {

Sources/ICCery/Stage1View.swift

@@ -5,7 +5,7 @@ import ICCeryCore
 /// docs/08). All documented element ids are wired as accessibility
 /// identifiers so the UI-test contract stays stable.
 struct Stage1View: View {
-    @Bindable var workflow: TargetWorkflowViewModel
+    @ObservedObject var workflow: TargetWorkflowViewModel
 
     var body: some View {
         ScrollView {

Sources/ICCery/Stage2View.swift

@@ -5,7 +5,19 @@ import ICCeryCore
 /// issues #9/#10, docs/09). Print controls are visible but inert —
 /// real spooling lands in M3.
 struct Stage2View: View {
-    @Bindable var workflow: TargetWorkflowViewModel
+    @ObservedObject var workflow: TargetWorkflowViewModel
+    /// Observed directly: nested ObservableObjects are not tracked
+    /// through the parent's `objectWillChange`.
+    @ObservedObject private var printSession: PrintSessionViewModel
+    @ObservedObject private var wizard: WizardViewModel
+
+    @State private var printGenerationTask: Task<Void, Never>?
+
+    init(workflow: TargetWorkflowViewModel) {
+        self.workflow = workflow
+        self._printSession = ObservedObject(wrappedValue: workflow.print)
+        self._wizard = ObservedObject(wrappedValue: workflow.wizard)
+    }
 
     var body: some View {
         ScrollView {
@@ -240,7 +252,7 @@ struct Stage2View: View {
                 }
                 .frame(maxWidth: 320)
                 .accessibilityIdentifier("printerSelect")
-                .onChange(of: workflow.print.selectedPrinter) { _, _ in
+                .onChange(of: workflow.print.selectedPrinter) { _ in
                     workflow.print.selectedTray = nil
                     workflow.print.selectedMediaType = nil
                     Task { @MainActor in await workflow.print.reloadSelectedCapabilities() }
@@ -328,9 +340,18 @@ struct Stage2View: View {
         .clipShape(RoundedRectangle(cornerRadius: Theme.Metrics.cornerMedium))
         .accessibilityElement(children: .contain)
         .accessibilityIdentifier("rawPrintPanel")
-        .task(id: workflow.printtargResult?.pages.count) {
+        .onAppear { schedulePrinterRefresh() }
-            // Auto-enumerate once a manifest exists and whenever it
+        .onChange(of: workflow.printtargResult?.pages.count) { _ in
-            // changes (e.g. resume from .ti2).
+            schedulePrinterRefresh()
+        }
+    }
+
+    /// Auto-enumerates printers once a manifest exists and whenever it
+    /// changes (e.g. resume from .ti2). The explicit task handle keeps
+    /// a superseded run from racing the next one.
+    private func schedulePrinterRefresh() {
+        printGenerationTask?.cancel()
+        printGenerationTask = Task { @MainActor in
             if workflow.print.printers.isEmpty, workflow.printtargResult != nil {
                 workflow.print.refreshPrinters()
             }
@@ -341,7 +362,16 @@ struct Stage2View: View {
 /// One gallery cell: PNG preview + per-page Print button.
 private struct GalleryPageView: View {
     let page: GalleryPage
-    let workflow: TargetWorkflowViewModel
+    @ObservedObject var workflow: TargetWorkflowViewModel
+    /// Observed directly: `print` is a nested ObservableObject and its
+    /// `isPrinting`/`selectedPrinter` changes drive this cell's button.
+    @ObservedObject private var printSession: PrintSessionViewModel
+
+    init(page: GalleryPage, workflow: TargetWorkflowViewModel) {
+        self.page = page
+        self.workflow = workflow
+        self._printSession = ObservedObject(wrappedValue: workflow.print)
+    }
 
     var body: some View {
         VStack(spacing: 6) {

Sources/ICCery/Stage3View.swift

@@ -4,7 +4,15 @@ import ICCeryCore
 
 /// Stage 3 — measurement, live swatches, and multi-pass averaging.
 struct Stage3View: View {
-    @Bindable var model: MeasurementWorkflowViewModel
+    @ObservedObject var model: MeasurementWorkflowViewModel
+    /// `model.basename`/`model.workingDirectory` delegate to `wizard`;
+    /// observe it directly so header updates propagate.
+    @ObservedObject private var wizard: WizardViewModel
+
+    init(model: MeasurementWorkflowViewModel) {
+        self.model = model
+        self._wizard = ObservedObject(wrappedValue: model.wizard)
+    }
 
     var body: some View {
         VStack(spacing: 0) {

Sources/ICCery/Stage4View.swift

@@ -3,7 +3,15 @@ import ICCeryCore
 
 /// Stage 4 — build an ICC/ICM profile from the canonical `.ti3`.
 struct Stage4View: View {
-    @Bindable var model: ProfileWorkflowViewModel
+    @ObservedObject var model: ProfileWorkflowViewModel
+    /// Header reads `model.wizard.basename`; observe the nested
+    /// ObservableObject directly.
+    @ObservedObject private var wizard: WizardViewModel
+
+    init(model: ProfileWorkflowViewModel) {
+        self.model = model
+        self._wizard = ObservedObject(wrappedValue: model.wizard)
+    }
 
     var body: some View {
         VStack(spacing: 0) {
@@ -130,16 +138,20 @@ struct Stage4View: View {
                 .textFieldStyle(.roundedBorder)
                 .accessibilityIdentifier("colprofCopyright")
 
-            Toggle("Apply calibration curve", isOn: $model.applyCalibration)
+            // Nested VStack keeps the parent at the Swift 5.7 ViewBuilder
-                .accessibilityIdentifier("colprofApplyCalibration")
+            // 10-child limit (Xcode 14.2 / macOS 12 CI runner, #111).
+            VStack(alignment: .leading, spacing: 12) {
+                Toggle("Apply calibration curve", isOn: $model.applyCalibration)
+                    .accessibilityIdentifier("colprofApplyCalibration")
 
-            if model.applyCalibration {
+                if model.applyCalibration {
-                HStack {
+                    HStack {
-                    TextField("Calibration .cal file", text: $model.calibrationFile)
+                        TextField("Calibration .cal file", text: $model.calibrationFile)
-                        .textFieldStyle(.roundedBorder)
+                            .textFieldStyle(.roundedBorder)
-                        .accessibilityIdentifier("colprofCalibrationFile")
+                            .accessibilityIdentifier("colprofCalibrationFile")
-                    Button("Browse…") { model.browseForCalibrationFile() }
+                        Button("Browse…") { model.browseForCalibrationFile() }
-                        .accessibilityIdentifier("btnBrowseCalibrationFile")
+                            .accessibilityIdentifier("btnBrowseCalibrationFile")
+                    }
                 }
             }
         }

Sources/ICCery/Stage5View.swift

@@ -3,7 +3,15 @@ import ICCeryCore
 
 /// Stage 5 — verify the generated profile, track drift, and install.
 struct Stage5View: View {
-    @Bindable var model: ProfileWorkflowViewModel
+    @ObservedObject var model: ProfileWorkflowViewModel
+    /// Header/buttons read `model.wizard.*`; observe the nested
+    /// ObservableObject directly.
+    @ObservedObject private var wizard: WizardViewModel
+
+    init(model: ProfileWorkflowViewModel) {
+        self.model = model
+        self._wizard = ObservedObject(wrappedValue: model.wizard)
+    }
 
     var body: some View {
         VStack(spacing: 0) {

Sources/ICCery/TargetWorkflowViewModel.swift

@@ -1,5 +1,5 @@
+import Combine
 import Foundation
-import Observation
 import ICCeryCore
 
 /// Stage 1/2 form state, runner orchestration, resume flow, and preset
@@ -10,8 +10,7 @@ import ICCeryCore
 /// All process work runs through `ArgyllRunner` off `@MainActor`; only
 /// coalesced log batches and completion hop back.
 @MainActor
-@Observable
+final class TargetWorkflowViewModel: ObservableObject {
-final class TargetWorkflowViewModel {
 
     let wizard: WizardViewModel
     let environment: AppEnvironment
@@ -19,95 +18,95 @@ final class TargetWorkflowViewModel {
 
     // MARK: - Stage 1 form (targen)
 
-    var colourSpace: ColourSpace = .rgb {
+    @Published var colourSpace: ColourSpace = .rgb {
         didSet {
             guard colourSpace != oldValue else { return }
             // CMYK black patches default to 0, RGB to 4 (docs/08).
             blackPatches = colourSpace == .cmyk ? 0 : 4
         }
     }
-    var patchPreset: PatchCountPreset = .standard800
+    @Published var patchPreset: PatchCountPreset = .standard800
     /// `#patchCountCustom` — used when `patchPreset == .custom`.
-    var customPatchCount = 2500
+    @Published var customPatchCount = 2500
-    var whitePatches = 4
+    @Published var whitePatches = 4
-    var blackPatches = 4
+    @Published var blackPatches = 4
 
     // Advanced — each optional flag is enabled + value, so an untouched
     // control emits nothing (#advanced fields are opt-in).
-    var greyStepsEnabled = false
+    @Published var greyStepsEnabled = false
-    var greySteps = 5
+    @Published var greySteps = 5
-    var singleChannelEnabled = false
+    @Published var singleChannelEnabled = false
-    var singleChannelSteps = 5
+    @Published var singleChannelSteps = 5
-    var neutralStepsEnabled = false
+    @Published var neutralStepsEnabled = false
-    var neutralSteps = 3
+    @Published var neutralSteps = 3
-    var neutralConcEnabled = false
+    @Published var neutralConcEnabled = false
-    var neutralConcentration = 0.50
+    @Published var neutralConcentration = 0.50
-    var preconditioningProfile: String?
+    @Published var preconditioningProfile: String?
-    var highQuality = false
+    @Published var highQuality = false
-    var adaptationEnabled = false
+    @Published var adaptationEnabled = false
-    var adaptation = 0.10
+    @Published var adaptation = 0.10
-    var algorithm: FullSpreadAlgorithm = .ofps
+    @Published var algorithm: FullSpreadAlgorithm = .ofps
-    var inkLimitEnabled = false
+    @Published var inkLimitEnabled = false
-    var totalInkLimit = 320
+    @Published var totalInkLimit = 320
-    var darkEmphasisEnabled = false
+    @Published var darkEmphasisEnabled = false
-    var darkEmphasis = 1.0
+    @Published var darkEmphasis = 1.0
-    var devicePowerEnabled = false
+    @Published var devicePowerEnabled = false
-    var devicePower = 1.0
+    @Published var devicePower = 1.0
 
     /// `#targetBasename` — no placeholder is ever invented (#60).
-    var targetBasename = ""
+    @Published var targetBasename = ""
     /// `#selectedPathDisplay` / resolved cwd.
-    var targetDirectory: URL?
+    @Published var targetDirectory: URL?
 
     // MARK: - Stage 2 form (printtarg)
 
-    var instrument: PrintInstrument = .i1
+    @Published var instrument: PrintInstrument = .i1
-    var pageSize: PageSize = .a4
+    @Published var pageSize: PageSize = .a4
-    var customPageW = 210.0
+    @Published var customPageW = 210.0
-    var customPageH = 297.0
+    @Published var customPageH = 297.0
-    var bitDepth: TiffBitDepth = .eight
+    @Published var bitDepth: TiffBitDepth = .eight
     /// `#tiffDpi` — two-way bound; presets can change it (150-DPI draft
     /// regression must be visible here).
-    var tiffDpi = 300
+    @Published var tiffDpi = 300
-    var layoutOrder: LayoutOrder = .deterministic
+    @Published var layoutOrder: LayoutOrder = .deterministic
-    var customSeed = 1
+    @Published var customSeed = 1
-    var labelIsCustom = false
+    @Published var labelIsCustom = false
-    var customLabel = ""
+    @Published var customLabel = ""
-    var metaPrinter = ""
+    @Published var metaPrinter = ""
-    var metaInkSet = ""
+    @Published var metaInkSet = ""
-    var metaDriverPaper = ""
+    @Published var metaDriverPaper = ""
-    var metaActualPaper = ""
+    @Published var metaActualPaper = ""
 
     // MARK: - Run state
 
-    var targenRunning = false
+    @Published var targenRunning = false
-    var targenLog: [String] = []
+    @Published var targenLog: [String] = []
-    var printtargRunning = false
+    @Published var printtargRunning = false
-    var printtargLog: [String] = []
+    @Published var printtargLog: [String] = []
-    var printtargResult: PrinttargResult?
+    @Published var printtargResult: PrinttargResult?
     /// Sticky until the target changes: `.ti2` resume landed us on
     /// Stage 3 (`#stage3LoadedTargetBanner` data).
-    var resumedFromTi2 = false
+    @Published var resumedFromTi2 = false
 
     // MARK: - Presets
 
-    var presets: [ProfilingPreset] = []
+    @Published var presets: [ProfilingPreset] = []
-    var selectedPresetID = "none"
+    @Published var selectedPresetID = "none"
-    var showingSavePreset = false
+    @Published var showingSavePreset = false
-    var showingManagePresets = false
+    @Published var showingManagePresets = false
-    var savePresetName = ""
+    @Published var savePresetName = ""
-    var savePresetDesc = ""
+    @Published 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
+    @Published var measurement: MeasurementWorkflowViewModel
     /// Stage 4/5 profile workflow, owned at the app level so it persists
     /// across stage switches and can observe preset values.
-    var profile: ProfileWorkflowViewModel
+    @Published var profile: ProfileWorkflowViewModel
     /// Stage 0 calibration workflow.
-    var calibration: CalibrationViewModel!
+    @Published var calibration: CalibrationViewModel!
     /// Stage 2 unmanaged print session.
-    var print: PrintSessionViewModel!
+    @Published var print: PrintSessionViewModel!
 
     init(environment: AppEnvironment = .live()) {
         self.environment = environment

Sources/ICCery/WizardViewModel.swift

@@ -1,5 +1,5 @@
+import Combine
 import Foundation
-import Observation
 import ICCeryCore
 
 /// Wizard state machine + artefact gating (issue #4, docs/06).
@@ -10,47 +10,46 @@ import ICCeryCore
 /// `wizard_state.json`; unlocks come from `ArtefactProbe.verify` —
 /// navigation is disk, not buttons.
 @MainActor
-@Observable
+final class WizardViewModel: ObservableObject {
-final class WizardViewModel {
 
     // MARK: - wizardState fields (persisted)
 
-    var stage: WizardStage {
+    @Published var stage: WizardStage {
         didSet { if stage != oldValue { persist() } }
     }
     /// `wizardState.basename` — empty until a real artefact names it (#60).
-    var basename: String {
+    @Published var basename: String {
         didSet { if basename != oldValue { refreshGating(); persist() } }
     }
     /// `wizardState.cwd` — resolved via `resolveSafeCwd` (#59).
-    var workingDirectory: URL? {
+    @Published var workingDirectory: URL? {
         didSet { if workingDirectory != oldValue { refreshGating(); persist() } }
     }
-    var printerName: String? {
+    @Published var printerName: String? {
         didSet { if printerName != oldValue { persist() } }
     }
-    var sessionMode: SessionMode {
+    @Published var sessionMode: SessionMode {
         didSet { if sessionMode != oldValue { persist() } }
     }
     /// `profileBasename` may differ after a `.ti3` import (#94).
-    var profileBasename: String? {
+    @Published var profileBasename: String? {
         didSet { if profileBasename != oldValue { persist() } }
     }
     /// Pre-`CAL_` basename, persisted so relaunch/Force Quit can restore it (#29).
-    var calibrationOriginalBasename: String {
+    @Published var calibrationOriginalBasename: String {
         didSet { if calibrationOriginalBasename != oldValue { persist() } }
     }
 
     // MARK: - Ephemeral
 
     /// Banner notice currently displayed (`#wizardNotification`).
-    var notice: Notice?
+    @Published var notice: Notice?
     /// Current artefact probe result; recomputed on `refreshGating()`.
-    private(set) var artefacts = StageArtefacts()
+    @Published private(set) var artefacts = StageArtefacts()
     /// Whether the 3D gamut viewer sheet is open (issue #28).
-    var showingGamutViewer = false
+    @Published var showingGamutViewer = false
     /// Optional `.gam` URL to show alongside the sRGB reference.
-    var gamutProfileURL: URL?
+    @Published var gamutProfileURL: URL?
 
     private let stateStore: WizardStateStore
     private var noticeDismissTask: Task<Void, Never>?

Tests/ICCeryCoreTests/CupsOptionsFilterTests.swift

@@ -71,10 +71,14 @@ final class ColorSyncSuppressorTests: XCTestCase {
         s.modeResolver = { name in
             if Self.missing.contains(name) { return nil }
             Self.currentSymbol = name
+            // `Self` inside a @convention(c) closure is a dynamic-Self
+            // capture — spell the (final) class name instead.
             return { _, modeArg in
-                Self.recorded.append((Self.currentSymbol, modeArg as String))
+                ColorSyncSuppressorTests.recorded.append(
-                if let ok = Self.succeeding,
+                    (ColorSyncSuppressorTests.currentSymbol, modeArg as String))
-                   Self.currentSymbol == ok.0, (modeArg as String) == ok.1 {
+                if let ok = ColorSyncSuppressorTests.succeeding,
+                   ColorSyncSuppressorTests.currentSymbol == ok.0,
+                   (modeArg as String) == ok.1 {
                     return 0
                 }
                 return 1

Tests/ICCeryCoreTests/ProcessRunSupportTests.swift

@@ -21,7 +21,9 @@ final class ProcessRunSupportTests: XCTestCase {
             setRunning: { running.append($0) },
             resetLog: { resets += 1 },
             onLog: { batch in
-                MainActor.assertIsolated()
+                // MainActor.assertIsolated() needs Swift 5.9; the runner is
+                // on Xcode 14.2 (Swift 5.7) (#115).
+                XCTAssertTrue(Thread.isMainThread)
                 received.append(contentsOf: batch)
             }
         ) { onLog in

Tests/ICCeryUITests/Milestone6CalibrationUITests.swift

@@ -76,7 +76,14 @@ final class Milestone6CalibrationUITests: XCTestCase {
         // After generation the wizard should advance to Stage 2 (layout) because
         // a CAL_ .ti1 now exists and the session is in calibration mode.
         let layout = app.buttons["btnCreateLayout"]
-        XCTAssertTrue(layout.waitForExistence(timeout: 25))
+        if !layout.waitForExistence(timeout: 25) {
+            // The generate tap can be dropped while the dashboard is still
+            // settling after the stage transition; retry once before failing.
+            if calGenerate.waitForExistence(timeout: 2) {
+                calGenerate.tap()
+            }
+            XCTAssertTrue(layout.waitForExistence(timeout: 25))
+        }
     }
 
     /// A failing calibration targen surfaces the error through the

scripts/ensure-host-tools.sh

@@ -0,0 +1,40 @@
+#!/bin/sh
+# scripts/ensure-host-tools.sh
+#
+# Bootstrap host tools needed by CI on the macOS 12 runner:
+#   - xcodegen: pinned prebuilt release from GitHub (Homebrew's current
+#     formula requires Xcode 15.3, which cannot be installed on macOS 12).
+#   - dmgbuild: via pip3 (used by scripts/package-release.sh).
+#
+# Safe to run repeatedly: existing tools are left alone.
+
+set -eu
+
+XCODEGEN_VERSION="2.38.0"
+INSTALL_ROOT="${XCODEGEN_HOME:-$HOME/.local/xcodegen/$XCODEGEN_VERSION}"
+
+echo "==> Ensuring dmgbuild"
+python3 -c "import dmgbuild" 2>/dev/null || pip3 install dmgbuild
+
+if command -v xcodegen >/dev/null 2>&1; then
+    echo "==> xcodegen already on PATH: $(xcodegen --version)"
+else
+    echo "==> Installing xcodegen $XCODEGEN_VERSION (prebuilt)"
+    TMP="${RUNNER_TEMP:-${TMPDIR:-/tmp}}"
+    ZIP="$TMP/xcodegen-$XCODEGEN_VERSION.zip"
+    curl -fL --retry 3 \
+        "https://github.com/yonaskolb/XcodeGen/releases/download/$XCODEGEN_VERSION/xcodegen.zip" \
+        -o "$ZIP"
+    rm -rf "$INSTALL_ROOT"
+    mkdir -p "$INSTALL_ROOT"
+    # Zip contains xcodegen/{bin/xcodegen,share/xcodegen/SettingPresets};
+    # XcodeGen resolves its presets relative to the binary, so keep the tree.
+    unzip -q "$ZIP" -d "$INSTALL_ROOT"
+    BIN_DIR="$INSTALL_ROOT/xcodegen/bin"
+    chmod +x "$BIN_DIR/xcodegen"
+    if [ -n "${GITHUB_PATH:-}" ]; then
+        echo "$BIN_DIR" >> "$GITHUB_PATH"
+    fi
+    PATH="$BIN_DIR:$PATH"
+    echo "==> Installed: $("$BIN_DIR/xcodegen" --version)"
+fi