Cleaner recording cancellation and macOS focus recovery

Cancel recordings cleanly, return to the original text field more reliably on macOS, and help us diagnose failures with clearer private reports.

• Reliable cancellation. Cancelled takes finish cleanup before the next recording starts.
• Return to your original window. On macOS, BridgeVoice raises the original window before restoring its text field. If the destination cannot be verified, your text stays available on the clipboard.