feat: Add full-screen receipt viewer, display trip participants in calendar, and restrict trip management options to creator.

lib/repositories/user_repository.dart

@@ -150,4 +150,43 @@ class UserRepository {
       throw Exception('Impossible de changer le mot de passe');
     }
   }
+
+  // Récupérer plusieurs utilisateurs par leurs IDs
+  Future<List<User>> getUsersByIds(List<String> uids) async {
+    if (uids.isEmpty) return [];
+
+    try {
+      // Firestore 'in' query supports up to 10 values.
+      // If we have more, we need to split into chunks.
+      List<User> users = [];
+
+      // Remove duplicates
+      final uniqueIds = uids.toSet().toList();
+
+      // Split into chunks of 10
+      for (var i = 0; i < uniqueIds.length; i += 10) {
+        final end = (i + 10 < uniqueIds.length) ? i + 10 : uniqueIds.length;
+        final chunk = uniqueIds.sublist(i, end);
+
+        final querySnapshot = await _firestore
+            .collection('users')
+            .where(FieldPath.documentId, whereIn: chunk)
+            .get();
+
+        for (var doc in querySnapshot.docs) {
+          final data = doc.data();
+          users.add(User.fromMap({...data, 'id': doc.id}));
+        }
+      }
+
+      return users;
+    } catch (e, stackTrace) {
+      _errorService.logError(
+        'UserRepository',
+        'Error retrieving users by IDs: $e',
+        stackTrace,
+      );
+      return [];
+    }
+  }
 }