Root cause: When a print completed with the camera stream popup open,
spawning a second ffmpeg process for finish photo capture caused a
conflict that froze the browser tab and video window.
Solution: Buffer the last frame from active camera streams. When
capturing finish photo, use the buffered frame if a stream is active
instead of spawning a new ffmpeg process.
Backend changes:
- camera.py: Added _last_frames buffer and get_buffered_frame() helper
- main.py: Photo capture uses buffered frame when stream is active
- main.py: Moved slow operations to background tasks (energy calc,
photo capture, smart plug, notifications, maintenance)
- archive.py: Fixed sync file write blocking event loop (asyncio.to_thread)
- printers.py: Added debug endpoint to simulate print completion
Frontend changes:
- useWebSocket.ts: Throttled printer status updates (100ms) to prevent
UI overload from rapid WebSocket messages
- useWebSocket.ts: Debounced archive invalidations (3s) to prevent
cascade of re-renders on print completion
- useWebSocket.test.ts: Updated tests for throttled/debounced handlers
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
maziggy