feat: implement separate GPS timeouts and update project documentation

GPS Timeout Improvements:
- Add separate GPS timeouts: 20s for initial fix, 2s for ongoing updates
- Resolve indoor GPS timeout issues that caused stream termination
- Prevent GPS stream from stopping immediately due to aggressive timeouts
- Enhanced GPS manager initialization with initial position fetch

Documentation Updates:
- Update TODO.md with v2.3.0-dev architecture completion status
- Update CLAUDE.md with GPS manager architecture details
- Document clean data flow and separate timeout strategy
- Update branch strategy to reflect current development state

Technical Notes:
- GPS manager now handles initial cold start with long timeout
- Ongoing updates use shorter timeout for responsive behavior
- Architecture ready for intelligent caching logic implementation
- All overlay functionality preserved while improving GPS reliability

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

lib/gps_service.dart

@@ -10,7 +10,7 @@ class GpsService {
       locationSettings: const LocationSettings(
         accuracy: LocationAccuracy.bestForNavigation,
         distanceFilter: 0,
-        timeLimit: Duration(milliseconds: 500), // Force updates every 500ms for faster GPS refresh
+        timeLimit: Duration(seconds: 2), // Short timeout for ongoing updates after initial fix
       ),
     );
   }