Migrate fires_flutter to flutter_map v6.1.0 and complete major null-safety fixes

- Updated Android build files: gradle plugin 8.2.2, gradle 8.3, SDK 34, minSdk 21
- Ran dart fix --apply for 87 automatic null-safety fixes
- Migrated flutter_map v6 API breaking changes:
  - MapOptions: center → initialCenter, zoom → initialZoom
  - layers → children structure
  - TileLayerOptions/MarkerLayerOptions/PolylineLayerOptions → TileLayer/MarkerLayer/PolylineLayer
  - Removed plugin_api.dart imports
  - Converted old plugin system (ZoomMapPlugin, AttributionPlugin, etc.) to direct widgets
  - Updated onTap callback signature: (TapPosition) → (TapPosition, LatLng)
- Migrated all marker/polyline creation to v6 API
- Fixed FlatButton → TextButton deprecation
- Fixed stackTrace access with catch(e, stackTrace) pattern
- Removed deprecated flutter_google_places_autocomplete dependency
- Removed deprecated dependencies: latlong, connectivity, launch_review
- Updated all imports from latlong → latlong2
- Placeholder implementation for places autocomplete (feature temporarily disabled)

Remaining tasks (non-blocking for build):
- Complete null-safety fixes for _location variables in genericMap.dart
- Fix theme.dart MaterialTheme parameter issues
- Fix customStepper.dart null-safety issues
- Final build and testing

lib/mainProd.dart

@@ -1,7 +1,27 @@
+import 'package:comunes_flutter/comunes_flutter.dart';
+import 'package:sentry_flutter/sentry_flutter.dart';
+
 import 'globals.dart' as globals;
 import 'mainCommon.dart';
 
-void main() {
+Future<void> main() async {
   globals.isDevelopment = false;
-  mainCommon([]);
-}
+
+  // Load secrets to get Sentry DSN
+  final secrets = await loadSecrets();
+
+  await SentryFlutter.init(
+    (options) {
+      options.dsn = secrets['sentryDSN'];
+    },
+    appRunner: () => mainCommon([]),
+  );
+}
+
+Future<Map<String, dynamic>> loadSecrets() async {
+  return await SecretLoader(
+          secretPath: globals.isDevelopment
+              ? 'assets/private-settings-dev.json'
+              : 'assets/private-settings.json')
+      .load();
+}