feat: Implement notifications feature, enhance profile settings with new sections, and integrate Firebase configurations for multiple environments.

lib/features/notifications/data/models/notification_model.dart

@@ -0,0 +1,53 @@
+class AppNotification {
+  final String id;
+  final String userId;
+  final String type; // 'connection' | 'message' | 'system' | 'update' | 'request'
+  final String title;
+  final String description;
+  final bool read;
+  final String? actionUrl;
+  final Map<String, String>? data;
+  final DateTime createdAt;
+
+  const AppNotification({
+    required this.id,
+    required this.userId,
+    required this.type,
+    required this.title,
+    required this.description,
+    required this.read,
+    this.actionUrl,
+    this.data,
+    required this.createdAt,
+  });
+
+  factory AppNotification.fromJson(Map<String, dynamic> json) {
+    return AppNotification(
+      id: json['id'] as String,
+      userId: json['userId'] as String? ?? '',
+      type: json['type'] as String? ?? 'system',
+      title: json['title'] as String? ?? '',
+      description: json['description'] as String? ?? '',
+      read: json['read'] as bool? ?? false,
+      actionUrl: json['actionUrl'] as String?,
+      data: json['data'] != null
+          ? Map<String, String>.from(json['data'] as Map)
+          : null,
+      createdAt: DateTime.parse(json['createdAt'] as String),
+    );
+  }
+
+  AppNotification copyWith({bool? read}) {
+    return AppNotification(
+      id: id,
+      userId: userId,
+      type: type,
+      title: title,
+      description: description,
+      read: read ?? this.read,
+      actionUrl: actionUrl,
+      data: data,
+      createdAt: createdAt,
+    );
+  }
+}