feat(activities): add autocomplete & what's new popup

Features:
- Add autocomplete support for Activity search with Google Places API.
- Add "What's New" popup system to showcase new features on app update.
- Implement logic to detect fresh installs vs updates.

Fixes:
- Switch API key handling to use Firebase config for Release mode support.
- Refactor map pins to be consistent (red pins).
- UI fixes on Create Trip page (overflow issues).

Refactor:
- Make WhatsNewDialog reusable by accepting features list as parameter.

lib/components/activities/activities_page.dart

@@ -7,6 +7,8 @@ import '../../blocs/activity/activity_state.dart';
 import '../../models/trip.dart';
 import '../../models/activity.dart';
 import '../../services/activity_cache_service.dart';
+import '../../services/activity_places_service.dart';
+import 'dart:async';
 
 import '../loading/laoding_content.dart';
 import '../../blocs/user/user_bloc.dart';
@@ -39,6 +41,14 @@ class _ActivitiesPageState extends State<ActivitiesPage>
   List<Activity> _approvedActivities = [];
   bool _isLoadingTripActivities = false;
 
+  // Autocomplete variables
+  List<Map<String, String>> _suggestions = [];
+  final LayerLink _layerLink = LayerLink();
+  OverlayEntry? _overlayEntry;
+  final FocusNode _searchFocusNode = FocusNode();
+  Timer? _debounceTimer;
+  bool _isLoadingSuggestions = false;
+
   bool _autoReloadInProgress =
       false; // Protection contre les rechargements en boucle
   int _lastAutoReloadTriggerCount =
@@ -105,6 +115,9 @@ class _ActivitiesPageState extends State<ActivitiesPage>
   void dispose() {
     _tabController.dispose();
     _searchController.dispose();
+    _searchFocusNode.dispose();
+    _debounceTimer?.cancel();
+    _hideSuggestions();
     super.dispose();
   }
 
@@ -278,42 +291,204 @@ class _ActivitiesPageState extends State<ActivitiesPage>
   }
 
   Widget _buildSearchBar(ThemeData theme) {
-    return Container(
-      padding: const EdgeInsets.all(16),
+    return CompositedTransformTarget(
+      link: _layerLink,
       child: Container(
-        decoration: BoxDecoration(
-          color: theme.colorScheme.surfaceContainerHighest.withValues(
-            alpha: 0.3,
-          ),
-          borderRadius: BorderRadius.circular(12),
-        ),
-        child: TextField(
-          controller: _searchController,
-          decoration: InputDecoration(
-            hintText: 'Rechercher restaurants, musées...',
-            hintStyle: TextStyle(
-              color: theme.colorScheme.onSurface.withValues(alpha: 0.6),
+        padding: const EdgeInsets.all(16),
+        child: Column(
+          children: [
+            Container(
+              decoration: BoxDecoration(
+                color: theme.colorScheme.surfaceContainerHighest.withValues(
+                  alpha: 0.3,
+                ),
+                borderRadius: BorderRadius.circular(12),
+              ),
+              child: TextField(
+                controller: _searchController,
+                focusNode: _searchFocusNode,
+                decoration: InputDecoration(
+                  hintText: 'Rechercher restaurants, musées...',
+                  hintStyle: TextStyle(
+                    color: theme.colorScheme.onSurface.withValues(alpha: 0.6),
+                  ),
+                  prefixIcon: Icon(
+                    Icons.search,
+                    color: theme.colorScheme.onSurface.withValues(alpha: 0.6),
+                  ),
+                  border: InputBorder.none,
+                  contentPadding: const EdgeInsets.symmetric(
+                    horizontal: 16,
+                    vertical: 12,
+                  ),
+                  suffixIcon: _isLoadingSuggestions
+                      ? const SizedBox(
+                          width: 20,
+                          height: 20,
+                          child: Padding(
+                            padding: EdgeInsets.all(10.0),
+                            child: CircularProgressIndicator(strokeWidth: 2),
+                          ),
+                        )
+                      : null,
+                ),
+                onChanged: _onSearchChanged,
+                onSubmitted: (value) {
+                  _hideSuggestions();
+                  if (value.isNotEmpty) {
+                    _performSearch(value);
+                  }
+                },
+              ),
             ),
-            prefixIcon: Icon(
-              Icons.search,
-              color: theme.colorScheme.onSurface.withValues(alpha: 0.6),
-            ),
-            border: InputBorder.none,
-            contentPadding: const EdgeInsets.symmetric(
-              horizontal: 16,
-              vertical: 12,
-            ),
-          ),
-          onSubmitted: (value) {
-            if (value.isNotEmpty) {
-              _performSearch(value);
-            }
-          },
+          ],
         ),
       ),
     );
   }
 
+  void _onSearchChanged(String value) {
+    if (_debounceTimer?.isActive ?? false) _debounceTimer!.cancel();
+
+    if (value.isEmpty) {
+      _hideSuggestions();
+      return;
+    }
+
+    _debounceTimer = Timer(const Duration(milliseconds: 300), () async {
+      setState(() {
+        _isLoadingSuggestions = true;
+      });
+
+      try {
+        final suggestions = await ActivityPlacesService().fetchSuggestions(
+          query: value,
+          lat: widget.trip.latitude,
+          lng: widget.trip.longitude,
+        );
+
+        if (mounted) {
+          setState(() {
+            _suggestions = suggestions;
+            _isLoadingSuggestions = false;
+          });
+
+          if (_suggestions.isNotEmpty) {
+            _showSuggestions();
+          } else {
+            _hideSuggestions();
+          }
+        }
+      } catch (e) {
+        if (mounted) {
+          setState(() {
+            _isLoadingSuggestions = false;
+          });
+        }
+      }
+    });
+  }
+
+  void _showSuggestions() {
+    _overlayEntry?.remove();
+    _overlayEntry = _createOverlayEntry();
+    Overlay.of(context).insert(_overlayEntry!);
+  }
+
+  void _hideSuggestions() {
+    _overlayEntry?.remove();
+    _overlayEntry = null;
+  }
+
+  OverlayEntry _createOverlayEntry() {
+    final renderBox = context.findRenderObject() as RenderBox;
+    final theme = Theme.of(context);
+    final size = renderBox.size;
+    final width = size.width - 32; // padding 16 * 2
+
+    return OverlayEntry(
+      builder: (context) => Positioned(
+        width: width,
+        child: CompositedTransformFollower(
+          link: _layerLink,
+          showWhenUnlinked: false,
+          offset: const Offset(16, 80), // Adjust vertical offset
+          child: Material(
+            elevation: 4,
+            borderRadius: BorderRadius.circular(12),
+            color: theme.colorScheme.surface,
+            child: ConstrainedBox(
+              constraints: const BoxConstraints(maxHeight: 250),
+              child: ListView.separated(
+                padding: EdgeInsets.zero,
+                shrinkWrap: true,
+                itemCount: _suggestions.length,
+                separatorBuilder: (context, index) => const Divider(height: 1),
+                itemBuilder: (context, index) {
+                  final suggestion = _suggestions[index];
+                  return ListTile(
+                    leading: const Icon(Icons.location_on_outlined),
+                    title: Text(
+                      suggestion['description'] ?? '',
+                      maxLines: 2,
+                      overflow: TextOverflow.ellipsis,
+                    ),
+                    onTap: () {
+                      _selectSuggestion(suggestion);
+                    },
+                  );
+                },
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+
+  Future<void> _selectSuggestion(Map<String, String> suggestion) async {
+    _hideSuggestions();
+    _searchController.text = suggestion['description']!;
+    _searchFocusNode.unfocus();
+
+    // Passer à l'onglet "Suggestion" si ce n'est pas déjà fait
+    if (_tabController.index != 2) {
+      _tabController.animateTo(2);
+    }
+
+    // Charger l'activité spécifique via le Bloc ou Service
+    // Ici on va utiliser le Bloc pour ajouter l'activité aux résultats de recherche
+    // Pour ça, il faudrait idéalement un événement "LoadSingleActivity" dans le Bloc
+    // Mais pour faire simple et rapide, on peut faire une recherche "exacte" ou hack:
+    // On charge l'activité manuellement et on l'ajoute comme si c'était un résultat de recherche.
+
+    setState(() {
+      _isLoadingSuggestions = true;
+    });
+
+    try {
+      final activity = await ActivityPlacesService().getActivityByPlaceId(
+        placeId: suggestion['placeId']!,
+        tripId: widget.trip.id!,
+      );
+
+      if (mounted && activity != null) {
+        // Injecter ce résultat unique dans le Bloc
+        context.read<ActivityBloc>().add(
+          RestoreCachedSearchResults(searchResults: [activity]),
+        );
+      }
+    } catch (e) {
+      ErrorService().showError(message: "Impossible de charger l'activité");
+    } finally {
+      if (mounted) {
+        setState(() {
+          _isLoadingSuggestions = false;
+        });
+      }
+    }
+  }
+
   Widget _buildCategoryTabs(ThemeData theme) {
     return Container(
       padding: const EdgeInsets.all(16),

lib/components/whats_new_dialog.dart

@@ -0,0 +1,140 @@
+import 'package:flutter/material.dart';
+import '../../services/whats_new_service.dart';
+
+class WhatsNewDialog extends StatelessWidget {
+  final VoidCallback onDismiss;
+  final List<WhatsNewItem> features;
+
+  const WhatsNewDialog({
+    super.key,
+    required this.onDismiss,
+    required this.features,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Dialog(
+      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(20)),
+      backgroundColor: theme.colorScheme.surface,
+      child: Padding(
+        padding: const EdgeInsets.all(24.0),
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            // Header
+            Row(
+              children: [
+                Container(
+                  padding: const EdgeInsets.all(8),
+                  decoration: BoxDecoration(
+                    color: theme.colorScheme.primaryContainer,
+                    shape: BoxShape.circle,
+                  ),
+                  child: Icon(
+                    Icons.auto_awesome,
+                    color: theme.colorScheme.primary,
+                    size: 24,
+                  ),
+                ),
+                const SizedBox(width: 16),
+                Expanded(
+                  child: Text(
+                    'Quoi de neuf ?',
+                    style: theme.textTheme.headlineSmall?.copyWith(
+                      fontWeight: FontWeight.bold,
+                    ),
+                  ),
+                ),
+              ],
+            ),
+            const SizedBox(height: 24),
+
+            // Features List
+            Flexible(
+              child: ListView.separated(
+                shrinkWrap: true,
+                itemCount: features.length,
+                separatorBuilder: (_, __) => const SizedBox(height: 16),
+                itemBuilder: (context, index) {
+                  final feature = features[index];
+                  return Row(
+                    crossAxisAlignment: CrossAxisAlignment.start,
+                    children: [
+                      Icon(
+                        feature.icon,
+                        color: theme.colorScheme.primary,
+                        size: 20,
+                      ),
+                      const SizedBox(width: 12),
+                      Expanded(
+                        child: Column(
+                          crossAxisAlignment: CrossAxisAlignment.start,
+                          children: [
+                            Text(
+                              feature.title,
+                              style: theme.textTheme.titleMedium?.copyWith(
+                                fontWeight: FontWeight.w600,
+                              ),
+                            ),
+                            const SizedBox(height: 4),
+                            Text(
+                              feature.description,
+                              style: theme.textTheme.bodyMedium?.copyWith(
+                                color: theme.colorScheme.onSurfaceVariant,
+                              ),
+                            ),
+                          ],
+                        ),
+                      ),
+                    ],
+                  );
+                },
+              ),
+            ),
+
+            const SizedBox(height: 32),
+
+            // Button
+            SizedBox(
+              width: double.infinity,
+              height: 50,
+              child: ElevatedButton(
+                onPressed: () {
+                  // Marquer comme vu via le service
+                  WhatsNewService().markCurrentVersionAsSeen();
+                  onDismiss();
+                },
+                style: ElevatedButton.styleFrom(
+                  backgroundColor: theme.colorScheme.primary,
+                  foregroundColor: theme.colorScheme.onPrimary,
+                  shape: RoundedRectangleBorder(
+                    borderRadius: BorderRadius.circular(12),
+                  ),
+                ),
+                child: const Text(
+                  'C\'est parti !',
+                  style: TextStyle(fontSize: 16, fontWeight: FontWeight.bold),
+                ),
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+class WhatsNewItem {
+  final IconData icon;
+  final String title;
+  final String description;
+
+  const WhatsNewItem({
+    required this.icon,
+    required this.title,
+    required this.description,
+  });
+}