v1.4.2

Fixed

Duplicate tray icon on second launch — added Windows single-instance
mutex (CreateMutexW). If HomRec is already running, second launch exits
immediately instead of creating another tray icon.

Microphone [Errno -9999] Unanticipated host error — now retries with
multiple channel/sample rate combinations (stereo/mono × 44100/48000/22050)
before giving up. Handles devices that only support specific configurations.

System audio [Errno -9999] — same retry logic applied to Stereo Mix device
open attempts.

Settings window not closing after Save — messagebox was shown after
dialog.destroy(), causing the window to become unresponsive. Fixed order:
show message first, then destroy.

Advanced Settings window blocking Settings from closing — added
grab_release() before destroy() so the parent window regains focus.

Version bumped to 1.4.2