Add GPS tracking functionality with location services integration

- Introduced TrackingRepository to manage activity tracking state and GPS points.
- Implemented LocationTrackingService for foreground GPS tracking using FusedLocationProviderClient.
- Created data models GpsPoint and TrackingState to represent tracking data.
- Enhanced TrackActivityScreen with UI for selecting activity type and displaying tracking status.
- Added LocationUtils for geospatial calculations, including distance tracking and loop closure detection.
- Updated build.gradle.kts to include Google Play Services Location dependency.

app/build.gradle.kts

@@ -117,6 +117,9 @@ dependencies {
     // MapLibre (free, no API key needed)
     implementation(libs.maplibre.compose)
 
+    // Google Play Services Location
+    implementation(libs.play.services.location)
+
     // Firebase (uncomment when google-services.json is added)
     // implementation(platform(libs.firebase.bom))
     // implementation(libs.firebase.messaging)