Remove dead code and add free UX features

REMOVED (dead code):
- CaptureMode enum (photo/video/boomerang) - never used
- selectedCaptureMode property
- CaptureControlling protocol file
- CenterStageControlling protocol
- SettingsViewModel CaptureControlling conformance

ADDED (free features):
- Double-tap to flip camera (front/back)
- Tap to focus (already built into MijickCamera)
- Volume button shutter (hardware shutter capture)
- Haptic feedback on capture, countdown ticks, and camera flip

NEW FILES:
- VolumeButtonObserver.swift - observes hardware volume buttons
- HiddenVolumeView - prevents system volume HUD

SelfieCam/Features/Camera/Views/CustomCameraScreen.swift

@@ -43,12 +43,16 @@ struct CustomCameraScreen: MCameraScreen {
     // Track camera position for runtime switching
     @State private var currentCameraPosition: CameraPosition?
     
+    // Volume button shutter observer
+    @StateObject private var volumeObserver = VolumeButtonObserver()
+
     var body: some View {
         ZStack {
-            // Camera preview with pinch gesture - Metal layer doesn't respect SwiftUI clipping
+            // Camera preview with gestures
             createCameraOutputView()
                 .ignoresSafeArea()
                 .scaleEffect(x: cameraSettings.isMirrorFlipped ? -1 : 1, y: 1) // Apply horizontal mirror flip
+                // Pinch to zoom
                 .gesture(
                     MagnificationGesture()
                         .updating($magnification) { currentState, gestureState, transaction in
@@ -68,6 +72,10 @@ struct CustomCameraScreen: MCameraScreen {
                             }
                         }
                 )
+                // Double-tap to flip camera (single tap focus is handled by MijickCamera)
+                .onTapGesture(count: 2) {
+                    flipCamera()
+                }
 
             // Ring light overlay - covers corners and creates rounded inner edge
             // When ring light is off, still show black corners to maintain rounded appearance
@@ -155,6 +163,10 @@ struct CustomCameraScreen: MCameraScreen {
                     .ignoresSafeArea()
                     .transition(.opacity)
             }
+            
+            // Hidden volume view to prevent system HUD when using volume buttons as shutter
+            HiddenVolumeView()
+                .frame(width: 0, height: 0)
         }
         .animation(.easeInOut(duration: 0.05), value: isShowingScreenFlash)
         .animation(.easeInOut(duration: 0.3), value: isCountdownActive)
@@ -191,6 +203,15 @@ struct CustomCameraScreen: MCameraScreen {
             }
             // Center Stage can be set immediately (system-level, not camera-view-level)
             applyCenterStage(cameraSettings.isCenterStageEnabled)
+            
+            // Start volume button observer for hardware shutter
+            volumeObserver.startObserving {
+                self.performCapture()
+            }
+        }
+        .onDisappear {
+            // Stop volume button observer
+            volumeObserver.stopObserving()
         }
         .onChange(of: cameraSettings.cameraPositionRaw) { _, newRaw in
             // Switch camera when position changes in settings
@@ -283,10 +304,15 @@ struct CustomCameraScreen: MCameraScreen {
         countdownSeconds = seconds
         isCountdownActive = true
         
+        // Initial haptic for countdown start
+        triggerHaptic(.light)
+
         Task { @MainActor in
             while countdownSeconds > 0 {
                 try? await Task.sleep(for: .seconds(1))
                 countdownSeconds -= 1
+                // Haptic tick for each countdown second
+                triggerHaptic(.light)
             }
 
             // Countdown finished, perform capture
@@ -297,6 +323,9 @@ struct CustomCameraScreen: MCameraScreen {
 
     /// Performs the actual capture with screen flash if needed
     private func performActualCapture() {
+        // Haptic feedback for capture
+        triggerHaptic(.medium)
+        
         print("performActualCapture called - shouldUseCustomScreenFlash: \(shouldUseCustomScreenFlash)")
         if shouldUseCustomScreenFlash {
             // Save original brightness and boost to max
@@ -382,4 +411,33 @@ struct CustomCameraScreen: MCameraScreen {
             Design.debugLog("Skin smoothing filter removed")
         }
     }
+    
+    // MARK: - Camera Gestures
+    
+    /// Flips between front and back camera with haptic feedback
+    private func flipCamera() {
+        triggerHaptic(.medium)
+        
+        let newPosition: CameraPosition = cameraPosition == .front ? .back : .front
+        Design.debugLog("Double-tap: flipping camera to \(newPosition)")
+        
+        Task {
+            do {
+                try await setCameraPosition(newPosition)
+                // Update settings to persist the change
+                cameraSettings.cameraPosition = newPosition
+                currentCameraPosition = newPosition
+            } catch {
+                Design.debugLog("Failed to flip camera: \(error)")
+            }
+        }
+    }
+    
+    // MARK: - Haptic Feedback
+    
+    /// Triggers haptic feedback with specified style
+    private func triggerHaptic(_ style: UIImpactFeedbackGenerator.FeedbackStyle) {
+        let generator = UIImpactFeedbackGenerator(style: style)
+        generator.impactOccurred()
+    }
 }

SelfieCam/Features/Camera/Views/VolumeButtonObserver.swift

@@ -0,0 +1,78 @@
+//
+//  VolumeButtonObserver.swift
+//  SelfieCam
+//
+//  Observes hardware volume button presses and triggers a callback.
+//  Used to enable shutter capture via volume buttons.
+//
+
+import AVFoundation
+import Combine
+import MediaPlayer
+import SwiftUI
+
+/// Observes volume button presses and calls the provided action.
+/// Hides the system volume HUD while observing.
+@MainActor
+final class VolumeButtonObserver: ObservableObject {
+    @Published private(set) var isObserving = false
+    
+    private var volumeObservation: NSKeyValueObservation?
+    private var onVolumeButtonPress: (@MainActor () -> Void)?
+    private var lastVolume: Float = 0.5
+    
+    /// Starts observing volume button presses
+    /// - Parameter action: Closure called when volume button is pressed
+    func startObserving(action: @escaping @MainActor () -> Void) {
+        guard !isObserving else { return }
+        
+        self.onVolumeButtonPress = action
+        self.isObserving = true
+        
+        let audioSession = AVAudioSession.sharedInstance()
+        
+        do {
+            try audioSession.setActive(true)
+            lastVolume = audioSession.outputVolume
+        } catch {
+            print("Failed to activate audio session: \(error)")
+            return
+        }
+        
+        // Observe volume changes using KVO
+        volumeObservation = audioSession.observe(\.outputVolume, options: [.new, .old]) { [weak self] _, change in
+            guard let newVolume = change.newValue,
+                  let oldVolume = change.oldValue,
+                  newVolume != oldVolume else { return }
+            
+            // Trigger capture on volume button press (either up or down)
+            Task { @MainActor [weak self] in
+                self?.onVolumeButtonPress?()
+            }
+        }
+    }
+    
+    /// Stops observing volume button presses
+    func stopObserving() {
+        volumeObservation?.invalidate()
+        volumeObservation = nil
+        onVolumeButtonPress = nil
+        isObserving = false
+        
+        try? AVAudioSession.sharedInstance().setActive(false, options: .notifyOthersOnDeactivation)
+    }
+}
+
+// MARK: - Hidden Volume View
+
+/// A hidden MPVolumeView that prevents the system volume HUD from appearing
+struct HiddenVolumeView: UIViewRepresentable {
+    func makeUIView(context: Context) -> MPVolumeView {
+        let volumeView = MPVolumeView(frame: .zero)
+        volumeView.alpha = 0.0001 // Nearly invisible but still functional
+        volumeView.isUserInteractionEnabled = false
+        return volumeView
+    }
+    
+    func updateUIView(_ uiView: MPVolumeView, context: Context) {}
+}

SelfieCam/Features/Settings/SettingsViewModel.swift

@@ -31,39 +31,6 @@ enum TimerOption: String, CaseIterable, Identifiable {
     }
 }
 
-// MARK: - Capture Mode
-
-enum CaptureMode: String, CaseIterable, Identifiable {
-    case photo = "photo"
-    case video = "video"
-    case boomerang = "boomerang"
-    
-    var id: String { rawValue }
-    
-    var displayName: String {
-        switch self {
-        case .photo: return String(localized: "Photo")
-        case .video: return String(localized: "Video")
-        case .boomerang: return String(localized: "Boomerang")
-        }
-    }
-    
-    var systemImage: String {
-        switch self {
-        case .photo: return "camera.fill"
-        case .video: return "video.fill"
-        case .boomerang: return "arrow.2.squarepath"
-        }
-    }
-    
-    var isPremium: Bool {
-        switch self {
-        case .photo: return false
-        case .video, .boomerang: return true
-        }
-    }
-}
-
 // MARK: - Settings ViewModel
 
 /// Observable settings view model with iCloud sync across all devices.
@@ -234,11 +201,6 @@ final class SettingsViewModel: RingLightConfigurable {
         }
     }
     
-    var selectedCaptureMode: CaptureMode {
-        get { CaptureMode(rawValue: cloudSync.data.selectedCaptureModeRaw) ?? .photo }
-        set { updateSettings { $0.selectedCaptureModeRaw = newValue.rawValue } }
-    }
-
     // MARK: - Camera Settings
 
     var flashMode: CameraFlashMode {
@@ -486,19 +448,3 @@ final class SettingsViewModel: RingLightConfigurable {
         ringSize >= Self.minRingSize
     }
 }
-
-// MARK: - CaptureControlling Conformance
-
-extension SettingsViewModel: CaptureControlling {
-    func startCountdown() async {
-        // Countdown handled by CameraViewModel
-    }
-    
-    func performCapture() {
-        // Capture handled by CameraViewModel
-    }
-    
-    func performFlashBurst() async {
-        // Flash handled by CameraViewModel
-    }
-}

SelfieCam/Shared/Protocols/CameraProtocols.swift

@@ -42,37 +42,6 @@ protocol CameraControllingAdvanced: AnyObject {
     func setZoomFactor(_ factor: CGFloat)
 }
 
-/// Protocol defining Center Stage control capabilities
-/// Center Stage automatically keeps users centered in the frame using the front camera
-protocol CenterStageControlling {
-    /// Whether Center Stage is currently available on this device
-    var isCenterStageAvailable: Bool { get }
-    
-    /// Whether Center Stage is currently enabled
-    var isCenterStageEnabled: Bool { get }
-    
-    /// Enable or disable Center Stage
-    /// - Parameter enabled: Whether to enable Center Stage
-    /// - Throws: If Center Stage cannot be configured
-    func setCenterStageEnabled(_ enabled: Bool) throws
-}
-
-// MARK: - Center Stage Default Implementation
-
-extension CenterStageControlling {
-    var isCenterStageAvailable: Bool {
-        AVCaptureDevice.isCenterStageEnabled || canEnableCenterStage
-    }
-    
-    private var canEnableCenterStage: Bool {
-        guard let device = AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .front) else {
-            return false
-        }
-        // Check if the device supports center stage by checking active format
-        return device.activeFormat.isCenterStageSupported
-    }
-}
-
 /// Combined protocol for full camera functionality
 protocol CameraControlling: CameraSessionManaging, PhotoCapturing, CameraPermissionHandling, CameraControllingAdvanced {}
 

SelfieCam/Shared/Protocols/CaptureControlling.swift

@@ -1,10 +0,0 @@
-protocol CaptureControlling {
-    var selectedTimer: TimerOption { get set }
-    var isGridVisible: Bool { get set }
-    var currentZoomFactor: Double { get set }
-    var selectedCaptureMode: CaptureMode { get set }
-
-    func startCountdown() async
-    func performCapture()
-    func performFlashBurst() async
-}