完善 OTG 相机有线传图：支持 Sony/Canon 自动识别，页面 detach 保持会话以便再次进入复连。

引入进程级 CameraTetheringSession 与共享 USB Browser；离开传图页仅取消 UI 回调，App 终止时再完整 shutdown 释放 PTP 与 Browser 资源。

Co-authored-by: Cursor <cursoragent@cursor.com>

suixinkan/Features/TravelAlbum/ViewModels/TravelAlbumViewModels.swift

@@ -435,6 +435,7 @@ final class WiredCameraTransferViewModel: ObservableObject {
     @Published var showCameraDisconnectedAlert = false
     @Published var showHelpDoc = false
     @Published var isRefreshingCameraFiles = false
+    @Published var isSearchingCamera = false
     @Published var deviceStorageInfo = DeviceStorageHelper.readStorageSnapshot()
     @Published var connectionState: CameraConnectionState = .disconnected
     @Published var errorMessage: String?
@@ -450,6 +451,9 @@ final class WiredCameraTransferViewModel: ObservableObject {
     private var lastProgressPersistDates: [String: Date] = [:]
     private var wasConnected = false
     private var disconnectAlertTask: Task<Void, Never>?
+    private var isTearingDownCamera = false
+    /// 用户主动离开页面时为 true，避免误弹「相机已断开」警告。
+    private var isLeavingPage = false
 
     /// 初始化有线传图 ViewModel。
     init(
@@ -458,17 +462,6 @@ final class WiredCameraTransferViewModel: ObservableObject {
     ) {
         self.context = context
         self.pipeline = CameraTransferPipeline(cameraService: cameraService)
-
-        pipeline.onConnectionStateChange = { [weak self] state in
-            Task { @MainActor in
-                self?.handleConnectionStateChange(state)
-            }
-        }
-        pipeline.onTasksUpdated = { [weak self] tasks in
-            Task { @MainActor in
-                await self?.applyPipelineTasks(tasks)
-            }
-        }
     }
 
     /// 配置上传 Sink 并启动相机连接。
@@ -478,6 +471,18 @@ final class WiredCameraTransferViewModel: ObservableObject {
         scenicID: Int,
         accountContext: AccountContext
     ) async {
+        isLeavingPage = false
+        pipeline.attachToUI(
+            onConnectionStateChange: { [weak self] state in
+                self?.handleConnectionStateChange(state)
+            },
+            onTasksUpdated: { [weak self] tasks in
+                Task { @MainActor in
+                    await self?.applyPipelineTasks(tasks)
+                }
+            }
+        )
+
         let accountCachePrefix = accountContext.accountCachePrefix ?? "guest_"
         let currentDownloadScope = CameraDownloadStorage.Scope(
             accountKey: accountCachePrefix,
@@ -505,15 +510,38 @@ final class WiredCameraTransferViewModel: ObservableObject {
         pipeline.configure(uploadSink: uploader, uploadEnabled: autoUpload, downloadScope: currentDownloadScope)
         refreshDeviceStorageInfo()
         loadPersistedPhotos()
-        await pipeline.connect()
-        connectionState = pipeline.connectionState
-        wasConnected = connectionState.isConnected
+
+        do {
+            await pipeline.connect()
+            connectionState = pipeline.connectionState
+            wasConnected = connectionState.isConnected
+
+            while !Task.isCancelled {
+                try await Task.sleep(nanoseconds: 1_000_000_000)
+            }
+        } catch is CancellationError {
+            // 用户返回或 task 取消。
+        } catch {
+            errorMessage = error.localizedDescription
+        }
+        detachFromUI()
     }
 
-    /// 断开相机连接。
+    /// 页面离开：仅 detach UI 回调，保持相机连接。
     func stop() async {
+        detachFromUI()
+    }
+
+    /// 页面离开：取消 UI 回调，不关闭相机会话。
+    func detachFromUI() {
+        guard !isTearingDownCamera else { return }
+        isTearingDownCamera = true
+        isLeavingPage = true
+        defer { isTearingDownCamera = false }
+
         disconnectAlertTask?.cancel()
-        await pipeline.disconnect()
+        showCameraDisconnectedAlert = false
+        pipeline.detachFromUI()
     }
 
     /// 刷新设备存储信息。
@@ -571,12 +599,25 @@ final class WiredCameraTransferViewModel: ObservableObject {
         errorMessage = nil
     }
 
-    /// 刷新相机文件列表。
+    /// 刷新相机文件列表；未连接时重新搜索 USB 相机。
     func refreshCameraFiles() async {
-        guard connectionState.isConnected, !isRefreshingCameraFiles else { return }
-        isRefreshingCameraFiles = true
-        defer { isRefreshingCameraFiles = false }
-        await pipeline.syncExistingPhotos()
+        if connectionState.isConnected {
+            guard !isRefreshingCameraFiles else { return }
+            isRefreshingCameraFiles = true
+            defer { isRefreshingCameraFiles = false }
+            await pipeline.syncExistingPhotos()
+            return
+        }
+        await restartCameraSearch()
+    }
+
+    /// 重新搜索 USB 相机。
+    func restartCameraSearch() async {
+        guard !connectionState.isConnected, !isSearchingCamera else { return }
+        isSearchingCamera = true
+        defer { isSearchingCamera = false }
+        await pipeline.restartCameraDiscovery()
+        connectionState = pipeline.connectionState
     }
 
     /// 批量上传按钮点击（三态：进入勾选 / 上传选中 / 取消选择）。
@@ -912,7 +953,7 @@ final class WiredCameraTransferViewModel: ObservableObject {
     }
 
     private func handleConnectionStateChange(_ state: CameraConnectionState) {
-        if wasConnected, !state.isConnected {
+        if wasConnected, !state.isConnected, !isLeavingPage {
             triggerCameraDisconnectedAlert()
         }
         wasConnected = state.isConnected