- Make stopAprs() async and await backend stop completion before
re-enabling the Start button, preventing race where a late stop
request kills newly started processes
- Add cache-buster param to EventSource URL to prevent browser
SSE connection reuse between stop/start cycles
- Capture aprs_active_device locally in stream_aprs_output so the
old thread's finally block doesn't release a device claimed by
a new session
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>