yumoqing eb3e98d567 fix: window close exits app + save dialog diagnostics
- AppDel: use NSWindow.willCloseNotification observer with visibility check
  instead of broken applicationShouldTerminateAfterLastWindowClosed logic
  (SwiftUI WindowGroup keeps hidden windows that blocked termination)
- finishWriting callback: use DispatchQueue.main.async instead of Task @MainActor
  (more reliable from non-main-thread AVFoundation callback)
- Add extensive NSLog diagnostics: callback invoked, file existence check,
  file size, status codes, nil checks
2026-06-25 21:08:59 +08:00
..