feat: ajout de la configuration des émulateurs Firebase et mise à jour des services pour utiliser le backend sécurisé

em2rp/lib/models/container_model.dart

@@ -242,6 +242,14 @@ class ContainerModel {
 
   /// Factory depuis Firestore
   factory ContainerModel.fromMap(Map<String, dynamic> map, String id) {
+    // Fonction helper pour convertir Timestamp ou String ISO en DateTime
+    DateTime? _parseDate(dynamic value) {
+      if (value == null) return null;
+      if (value is Timestamp) return value.toDate();
+      if (value is String) return DateTime.tryParse(value);
+      return null;
+    }
+
     final List<dynamic> equipmentIdsRaw = map['equipmentIds'] ?? [];
     final List<String> equipmentIds = equipmentIdsRaw.map((e) => e.toString()).toList();
 
@@ -262,8 +270,8 @@ class ContainerModel {
       equipmentIds: equipmentIds,
       eventId: map['eventId'],
       notes: map['notes'],
-      createdAt: (map['createdAt'] as Timestamp?)?.toDate() ?? DateTime.now(),
-      updatedAt: (map['updatedAt'] as Timestamp?)?.toDate() ?? DateTime.now(),
+      createdAt: _parseDate(map['createdAt']) ?? DateTime.now(),
+      updatedAt: _parseDate(map['updatedAt']) ?? DateTime.now(),
       history: history,
     );
   }
@@ -342,8 +350,16 @@ class ContainerHistoryEntry {
   });
 
   factory ContainerHistoryEntry.fromMap(Map<String, dynamic> map) {
+    // Helper pour parser la date
+    DateTime _parseDate(dynamic value) {
+      if (value == null) return DateTime.now();
+      if (value is Timestamp) return value.toDate();
+      if (value is String) return DateTime.tryParse(value) ?? DateTime.now();
+      return DateTime.now();
+    }
+
     return ContainerHistoryEntry(
-      timestamp: (map['timestamp'] as Timestamp?)?.toDate() ?? DateTime.now(),
+      timestamp: _parseDate(map['timestamp']),
       action: map['action'] ?? '',
       equipmentId: map['equipmentId'],
       previousValue: map['previousValue'],