7d111ca202
- Remove all shared state variables (unit, theme, GPS data, overlay status) - Keep only local widget state (_errorMessage, _isInBackground, timer) - Replace GPS initialization with context.read<GpsDataManager>().initialize() - Replace overlay show/close/toggle with OverlayProvider methods - Replace theme/unit cycling with SettingsProvider.cycleTheme/Unit() - Remove isOverlayMode parameter (not used, overlay runs in separate isolate) - Wrap build with Selector<SettingsProvider, ColorTheme> for scaffold background - Use Selector<GpsDataManager, double> for speed display (rebuilds only on speed change) - Use Selector<SettingsProvider, String> for unit label (rebuilds only on unit change) - Use Selector<GpsDataManager, (heading, displayHeading)> for compass (rebuilds only on heading change) - Use context.read<> for event handlers (non-rebuilding access) - Simplify dispose() - only cancel background heartbeat timer and disable wakelock - Background heartbeat uses OverlayProvider.pushCurrentData() instead of inline logic - setState remains ONLY for _errorMessage (purely local error UI state) - Remove unused imports (speed_unit.dart, processed_gps_data.dart) - Portrait and landscape layouts both use Provider pattern