Critical fixes:
- CamoufoxPool: shared browser/context singleton — LiveSyncService and
CamoufoxBridge now share the same context, so real-time synced cookies
are visible to adapter pages
- CamoufoxBridge uses pool instead of creating isolated contexts
- LiveSyncService: initial full export-state from Chrome before watching
- Cookie debounce batching: 50ms window with deduplication
- camoufox stop command: finds and kills server process
- Python launcher: Windows-compatible (threading.Event vs signal.pause)