temp

Gaze/Constants/EyeTrackingConstants.swift

@@ -8,7 +8,10 @@
 import Combine
 import Foundation
 
-class EyeTrackingConstants: ObservableObject {
+/// Thread-safe configuration holder for eye tracking thresholds.
+/// Uses @unchecked Sendable because all access is via the shared singleton
+/// and the @Published properties are only mutated from the main thread.
+final class EyeTrackingConstants: ObservableObject, @unchecked Sendable {
     static let shared = EyeTrackingConstants()
     
     // MARK: - Logging

Gaze/Models/AppSettings.swift

@@ -9,7 +9,7 @@ import Foundation
 
 // MARK: - Reminder Size
 
-enum ReminderSize: String, Codable, CaseIterable {
+enum ReminderSize: String, Codable, CaseIterable, Sendable {
     case small
     case medium
     case large
@@ -31,7 +31,7 @@ enum ReminderSize: String, Codable, CaseIterable {
     }
 }
 
-struct AppSettings: Codable, Equatable, Hashable {
+struct AppSettings: Codable, Equatable, Hashable, Sendable {
     var lookAwayTimer: TimerConfiguration
     var lookAwayCountdownSeconds: Int
     var blinkTimer: TimerConfiguration

Gaze/Models/SmartModeSettings.swift

@@ -7,7 +7,7 @@
 
 import Foundation
 
-struct SmartModeSettings: Codable, Equatable, Hashable {
+struct SmartModeSettings: Codable, Equatable, Hashable, Sendable {
     var autoPauseOnFullscreen: Bool
     var autoPauseOnIdle: Bool
     var trackUsage: Bool

Gaze/Models/TimerConfiguration.swift

@@ -7,7 +7,7 @@
 
 import Foundation
 
-struct TimerConfiguration: Codable, Equatable, Hashable {
+struct TimerConfiguration: Codable, Equatable, Hashable, Sendable {
     var enabled: Bool
     var intervalSeconds: Int
     

Gaze/Models/UserTimer.swift

@@ -9,7 +9,7 @@ import Foundation
 import SwiftUI
 
 /// Represents a user-defined timer with customizable properties
-struct UserTimer: Codable, Equatable, Identifiable, Hashable {
+struct UserTimer: Codable, Equatable, Identifiable, Hashable, Sendable {
     let id: String
     var title: String
     var type: UserTimerType
@@ -100,7 +100,7 @@ extension Color {
 }
 
 /// Type of user timer - subtle or overlay
-enum UserTimerType: String, Codable, CaseIterable, Identifiable {
+enum UserTimerType: String, Codable, CaseIterable, Identifiable, Sendable {
     case subtle
     case overlay
 

Gaze/Protocols/TimeProviding.swift

@@ -8,7 +8,7 @@
 import Foundation
 
 /// Protocol for providing current time, enabling deterministic tests.
-protocol TimeProviding {
+protocol TimeProviding: Sendable {
     /// Returns the current date/time
     func now() -> Date
 }
@@ -21,7 +21,7 @@ struct SystemTimeProvider: TimeProviding {
 }
 
 /// Test implementation that allows manual time control
-final class MockTimeProvider: TimeProviding {
+final class MockTimeProvider: TimeProviding, @unchecked Sendable {
     private var currentTime: Date
     
     init(startTime: Date = Date()) {

Gaze/Services/EyeTrackingService.swift

@@ -60,7 +60,7 @@ class EyeTrackingService: NSObject, ObservableObject {
     // MARK: - Processing Result
     
     /// Result struct for off-main-thread processing
-    private struct ProcessingResult {
+    private struct ProcessingResult: Sendable {
         var faceDetected: Bool = false
         var isEyesClosed: Bool = false
         var userLookingAtScreen: Bool = true
@@ -271,7 +271,7 @@ class EyeTrackingService: NSObject, ObservableObject {
     }
     
     /// Non-isolated gaze detection result
-    private struct GazeResult {
+    private struct GazeResult: Sendable {
         var lookingAway: Bool = false
         var leftPupilRatio: Double?
         var rightPupilRatio: Double?

Gaze/Services/FullscreenDetectionService.swift

@@ -83,13 +83,13 @@ final class FullscreenDetectionService: ObservableObject {
     
     // Factory method to safely create instances from non-main actor contexts
     static func create(
-        permissionManager: ScreenCapturePermissionManaging = ScreenCapturePermissionManager.shared,
-        environmentProvider: FullscreenEnvironmentProviding = SystemFullscreenEnvironmentProvider()
+        permissionManager: ScreenCapturePermissionManaging? = nil,
+        environmentProvider: FullscreenEnvironmentProviding? = nil
     ) async -> FullscreenDetectionService {
         await MainActor.run {
             return FullscreenDetectionService(
-                permissionManager: permissionManager,
-                environmentProvider: environmentProvider
+                permissionManager: permissionManager ?? ScreenCapturePermissionManager.shared,
+                environmentProvider: environmentProvider ?? SystemFullscreenEnvironmentProvider()
             )
         }
     }

Gaze/Services/PupilDetector.swift

@@ -20,28 +20,33 @@ import Accelerate
 import ImageIO
 import UniformTypeIdentifiers
 
-struct PupilPosition: Equatable {
+struct PupilPosition: Equatable, Sendable {
     let x: CGFloat
     let y: CGFloat
 }
 
-struct EyeRegion {
+struct EyeRegion: Sendable {
     let frame: CGRect
     let center: CGPoint
     let origin: CGPoint
 }
 
 /// Calibration state for adaptive thresholding (matches Python Calibration class)
-final class PupilCalibration {
+final class PupilCalibration: @unchecked Sendable {
+    private let lock = NSLock()
     private let targetFrames = 20
     private var thresholdsLeft: [Int] = []
     private var thresholdsRight: [Int] = []
     
     var isComplete: Bool {
-        thresholdsLeft.count >= targetFrames && thresholdsRight.count >= targetFrames
+        lock.lock()
+        defer { lock.unlock() }
+        return thresholdsLeft.count >= targetFrames && thresholdsRight.count >= targetFrames
     }
     
     func threshold(forSide side: Int) -> Int {
+        lock.lock()
+        defer { lock.unlock() }
         let thresholds = side == 0 ? thresholdsLeft : thresholdsRight
         guard !thresholds.isEmpty else { return 50 }
         return thresholds.reduce(0, +) / thresholds.count
@@ -49,6 +54,8 @@ final class PupilCalibration {
     
     func evaluate(eyeData: UnsafePointer<UInt8>, width: Int, height: Int, side: Int) {
         let bestThreshold = findBestThreshold(eyeData: eyeData, width: width, height: height)
+        lock.lock()
+        defer { lock.unlock() }
         if side == 0 {
             thresholdsLeft.append(bestThreshold)
         } else {
@@ -106,13 +113,15 @@ final class PupilCalibration {
     }
     
     func reset() {
+        lock.lock()
+        defer { lock.unlock() }
         thresholdsLeft.removeAll()
         thresholdsRight.removeAll()
     }
 }
 
 /// Performance metrics for pupil detection
-struct PupilDetectorMetrics {
+struct PupilDetectorMetrics: Sendable {
     var lastProcessingTimeMs: Double = 0
     var averageProcessingTimeMs: Double = 0
     var frameCount: Int = 0
@@ -126,7 +135,11 @@ struct PupilDetectorMetrics {
     }
 }
 
-final class PupilDetector {
+final class PupilDetector: @unchecked Sendable {
+    
+    // MARK: - Thread Safety
+    
+    private static let lock = NSLock()
     
     // MARK: - Configuration
     
@@ -134,14 +147,14 @@ final class PupilDetector {
     static var enablePerformanceLogging = false
     static var frameSkipCount = 10  // Process every Nth frame
     
-    // MARK: - State
+    // MARK: - State (protected by lock)
     
-    private static var debugImageCounter = 0
-    private static var frameCounter = 0
-    private static var lastPupilPositions: (left: PupilPosition?, right: PupilPosition?) = (nil, nil)
+    private static var _debugImageCounter = 0
+    private static var _frameCounter = 0
+    private static var _lastPupilPositions: (left: PupilPosition?, right: PupilPosition?) = (nil, nil)
+    private static var _metrics = PupilDetectorMetrics()
     
     static let calibration = PupilCalibration()
-    static var metrics = PupilDetectorMetrics()
     
     // MARK: - Precomputed Tables
     
@@ -182,7 +195,7 @@ final class PupilDetector {
     
     /// Detects pupil position with frame skipping for performance
     /// Returns cached result on skipped frames
-    static func detectPupil(
+    nonisolated static func detectPupil(
         in pixelBuffer: CVPixelBuffer,
         eyeLandmarks: VNFaceLandmarkRegion2D,
         faceBoundingBox: CGRect,

Gaze/Views/Containers/SettingsWindowView.swift

@@ -62,7 +62,7 @@ final class SettingsWindowPresenter {
         window.titleVisibility = .hidden
         window.titlebarAppearsTransparent = true
         window.toolbarStyle = .unified
-        window.toolbar = NSToolbar()
+        window.showsToolbarButton = false
         window.center()
         window.setFrameAutosaveName("SettingsWindow")
         window.isReleasedWhenClosed = false
@@ -103,8 +103,10 @@ final class SettingsWindowPresenter {
     }
 
     deinit {
-        Task { @MainActor in
-            removeCloseObserver()
+        // Capture observer locally to avoid actor isolation issues
+        // NotificationCenter.removeObserver is thread-safe
+        if let observer = closeObserver {
+            NotificationCenter.default.removeObserver(observer)
         }
     }
 }
@@ -133,6 +135,15 @@ struct SettingsWindowView: View {
                     .listStyle(.sidebar)
                 } detail: {
                     detailView(for: selectedSection)
+                }.onReceive(
+                    NotificationCenter.default.publisher(
+                        for: Notification.Name("SwitchToSettingsTab"))
+                ) { notification in
+                    if let tab = notification.object as? Int,
+                        let section = SettingsSection(rawValue: tab)
+                    {
+                        selectedSection = section
+                    }
                 }
 
                 #if DEBUG
@@ -161,15 +172,6 @@ struct SettingsWindowView: View {
                 minHeight: 900
             )
         #endif
-        .onReceive(
-            NotificationCenter.default.publisher(for: Notification.Name("SwitchToSettingsTab"))
-        ) { notification in
-            if let tab = notification.object as? Int,
-                let section = SettingsSection(rawValue: tab)
-            {
-                selectedSection = section
-            }
-        }
     }
 
     @ViewBuilder