fix(iOS): show recorder errors as full-screen overlay instead of fleeting toast

- Added recorderErrorMessage @Published var for persistent error display
- Recording errors now shown as overlay with error details + Dismiss button
- presentShareSheet now logs errors and sets recorderErrorMessage on failure
- Errors like 'No window scene' or 'No view controller' visible on screen

Sources/MiniPlayerApp.swift

@@ -440,6 +440,30 @@ struct PlayerContentView: View {
             // 播放状态指示（loading/buffering/error）
             PlayerStatusOverlay(bridge: bridge)
             
+            // 录制错误覆盖层（显示在界面上不会一闪而过）
+            #if os(iOS)
+            if let errMsg = bridge.recorderErrorMessage {
+                VStack(spacing: 16) {
+                    Image(systemName: "exclamationmark.triangle.fill")
+                        .font(.system(size: 36))
+                        .foregroundColor(.orange)
+                    Text("Recording Error")
+                        .font(.headline).foregroundColor(.white)
+                    Text(errMsg)
+                        .font(.system(size: 14))
+                        .foregroundColor(.white.opacity(0.8))
+                        .multilineTextAlignment(.center)
+                        .padding(.horizontal, 40)
+                    Button("Dismiss") {
+                        bridge.recorderErrorMessage = nil
+                    }
+                    .buttonStyle(.borderedProminent)
+                }
+                .frame(maxWidth: .infinity, maxHeight: .infinity)
+                .background(Color.black.opacity(0.75))
+            }
+            #endif
+            
             // 左上角应用图标 — iOS 锁屏控制 / macOS 切换控制栏
             MiniPlayerIcon()
                 .frame(width: 32, height: 32)

Sources/PlayerBridge.swift

@@ -124,6 +124,7 @@ final class PlayerBridge: ObservableObject {
     let hlsRecorder = HLSRecorder()
     let pipController = PiPController()
     @Published var pendingExportURL: URL?
+    @Published var recorderErrorMessage: String?  // 录制错误直接显示在界面上
     #endif
     // 诊断日志
     private var diagLogURL: URL?
@@ -178,12 +179,14 @@ final class PlayerBridge: ObservableObject {
         
         #if os(iOS)
         hlsRecorder.onRecordingSaved = { [weak self] url in
-            NSLog("[MiniPlayer] onRecordingSaved called: %@", url.lastPathComponent)
+            NSLog("[MiniPlayer] onRecordingSaved: %@", url.lastPathComponent)
+            self?.recorderErrorMessage = nil
             self?.showToast("Saved: \(url.lastPathComponent)")
-            // 直接用 UIKit present，不依赖 SwiftUI sheet binding
             self?.presentShareSheet(for: url)
         }
         hlsRecorder.onError = { [weak self] msg in
+            NSLog("[MiniPlayer] onError: %@", msg)
+            self?.recorderErrorMessage = msg
             self?.showToast(msg)
         }
         #endif
@@ -192,22 +195,29 @@ final class PlayerBridge: ObservableObject {
     #if os(iOS)
     /// 直接通过 UIKit present UIActivityViewController，绕过 SwiftUI sheet 可能的多 sheet 冲突
     func presentShareSheet(for url: URL) {
+        NSLog("[MiniPlayer] presentShareSheet: %@", url.lastPathComponent)
         guard let windowScene = UIApplication.shared.connectedScenes
             .compactMap({ $0 as? UIWindowScene })
             .first(where: { $0.activationState == .foregroundActive })
             ?? UIApplication.shared.connectedScenes.compactMap({ $0 as? UIWindowScene }).first
-        else { return }
+        else {
+            recorderErrorMessage = "No window scene available"
+            return
+        }
         
         var topVC = windowScene.keyWindow?.rootViewController
             ?? windowScene.windows.first(where: { !$0.isHidden && $0.bounds.size != .zero })?.rootViewController
         while let presented = topVC?.presentedViewController { topVC = presented }
         
-        let activityVC = UIActivityViewController(activityItems: [url], applicationActivities: nil)
-        activityVC.completionWithItemsHandler = { _, _, _, _ in
-            // 录制完成后可以删掉临时文件？不，用户可能需要再次分享
+        guard let presenter = topVC else {
+            recorderErrorMessage = "No view controller to present share sheet"
+            return
         }
-        topVC?.present(activityVC, animated: true)
-        NSLog("[MiniPlayer] presentShareSheet: presented for %@", url.lastPathComponent)
+        
+        let activityVC = UIActivityViewController(activityItems: [url], applicationActivities: nil)
+        activityVC.completionWithItemsHandler = { _, _, _, _ in }
+        presenter.present(activityVC, animated: true)
+        NSLog("[MiniPlayer] presentShareSheet: presented successfully")
     }
 
     /// 配置 AVAudioSession，支持后台音频和 PiP