fix: corregir flujo completo de servicio y geocodificación

- Service.fromJson: lat/lng con Decimal de Prisma llegaban como string y
  el cast 'as num?' lanzaba TypeError silencioso → lista de servicios vacía.
  Mismo patrón que average_score, fix: double.tryParse(?.toString())
- service_status: agregar enumToStringService que mapea el enum de Flutter
  al string que espera el DTO del backend ('pending','accepted', etc.).
  changeServiceStatus enviaba el índice entero → @IsEnum rechazaba → el
  profesional no podía aceptar ni rechazar solicitudes
- maps_service: agregar MapsService.reverseGeocode que usa el Geocoder del
  Maps JS SDK ya cargado, sin requerir la Geocoding API habilitada por separado
- dashboard_view: _reverseGeocode usa el JS Geocoder en vez del endpoint HTTP

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/models/service.dart

@@ -65,8 +65,9 @@ class Service {
       userScored: doc['user_scored'] as bool? ?? false,
       address: doc['address'] as String? ?? '',
       aditionalAddress: (doc['additional_address'] ?? doc['aditional_address']) as String? ?? '',
-      latitude: (doc['latitude'] as num?)?.toDouble() ?? 0.0,
-      longitude: (doc['longitude'] as num?)?.toDouble() ?? 0.0,
+      // Prisma Decimal fields serialize as JSON strings — same pattern as average_score
+      latitude: double.tryParse(doc['latitude']?.toString() ?? '') ?? 0.0,
+      longitude: double.tryParse(doc['longitude']?.toString() ?? '') ?? 0.0,
       day: (doc['day']?.toString() ?? '').split('T').first,
       createdAt: doc['created_at']?.toString() ?? '',
       description: doc['description'] as String? ?? '',