feat: dashboard city validation + professionals by location

- Professionals filtered by user city + proximity (lat/lng) to selected address
- ProfessionalsProvider: setLocationContext(city, lat, lng) updates filter and reloads
- Dashboard: detect city mismatch after reverse geocode, block booking if wrong city
- Dashboard: autocomplete biased toward user's city
- Dashboard: setLocationContext called before navigating to professionals list
- Dashboard: keyboard no longer shifts map layout on tablet (MediaQuery viewInsets=0)

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

lib/providers/professionals_provider.dart

@@ -6,24 +6,40 @@ class ProfessionalsProvider extends ChangeNotifier {
   List<UsuarioProfesional> professionals = [];
   bool isLoading = true;
   bool _initialized = false;
+  String? _locationCity;
+  double? _locationLat;
+  double? _locationLng;
   final _api = ApiService.instance;
 
   void updateCity(String? city) {
-    // Only used to trigger the initial load when auth becomes available.
     if (!_initialized) {
       _initialized = true;
+      _locationCity = city;
       getProfessionals();
     }
   }
 
+  void setLocationContext({required String? city, required double lat, required double lng}) {
+    if (city != null && city.isNotEmpty) _locationCity = city;
+    _locationLat = lat;
+    _locationLng = lng;
+    getProfessionals();
+  }
+
   Future<void> getProfessionals({String? search}) async {
     isLoading = true;
     notifyListeners();
     try {
-      final path = (search != null && search.trim().isNotEmpty)
-          ? '/professionals?search=${Uri.encodeComponent(search.trim())}'
-          : '/professionals';
-      final res = await _api.get(path);
+      final params = <String, String>{};
+      if (search != null && search.trim().isNotEmpty) params['search'] = search.trim();
+      if (_locationCity != null && _locationCity!.isNotEmpty) params['city'] = _locationCity!.trim();
+      if (_locationLat != null) params['lat'] = _locationLat.toString();
+      if (_locationLng != null) params['lng'] = _locationLng.toString();
+
+      final query = params.isEmpty
+          ? ''
+          : '?${params.entries.map((e) => '${e.key}=${Uri.encodeComponent(e.value)}').join('&')}';
+      final res = await _api.get('/professionals$query');
       final list = (res is Map ? res['data'] : res) as List;
       professionals = list
           .map((e) => UsuarioProfesional.fromDocument(e as Map<String, dynamic>))