phase 1 complete - local storage and aching

lib/data/local/models/item.dart

@@ -0,0 +1,85 @@
+/// Data model representing an item stored in local storage.
+/// 
+/// This model is used for storing items (e.g., image metadata or records)
+/// in the local database. Each item has a unique ID and can contain
+/// arbitrary JSON data.
+class Item {
+  /// Unique identifier for the item.
+  final String id;
+
+  /// JSON-serializable data stored with the item.
+  final Map<String, dynamic> data;
+
+  /// Timestamp when the item was created (milliseconds since epoch).
+  final int createdAt;
+
+  /// Timestamp when the item was last updated (milliseconds since epoch).
+  final int updatedAt;
+
+  /// Creates an [Item] instance.
+  /// 
+  /// [id] - Unique identifier for the item.
+  /// [data] - JSON-serializable data to store.
+  /// [createdAt] - Creation timestamp (defaults to current time).
+  /// [updatedAt] - Update timestamp (defaults to current time).
+  Item({
+    required this.id,
+    required this.data,
+    int? createdAt,
+    int? updatedAt,
+  })  : createdAt = createdAt ?? DateTime.now().millisecondsSinceEpoch,
+        updatedAt = updatedAt ?? DateTime.now().millisecondsSinceEpoch;
+
+  /// Creates an [Item] from a database row (Map).
+  factory Item.fromMap(Map<String, dynamic> map) {
+    return Item(
+      id: map['id'] as String,
+      data: map['data'] as Map<String, dynamic>,
+      createdAt: map['created_at'] as int,
+      updatedAt: map['updated_at'] as int,
+    );
+  }
+
+  /// Converts the [Item] to a Map for database storage.
+  Map<String, dynamic> toMap() {
+    return {
+      'id': id,
+      'data': data,
+      'created_at': createdAt,
+      'updated_at': updatedAt,
+    };
+  }
+
+  /// Creates a copy of this [Item] with updated fields.
+  Item copyWith({
+    String? id,
+    Map<String, dynamic>? data,
+    int? createdAt,
+    int? updatedAt,
+  }) {
+    return Item(
+      id: id ?? this.id,
+      data: data ?? this.data,
+      createdAt: createdAt ?? this.createdAt,
+      updatedAt: updatedAt ?? this.updatedAt,
+    );
+  }
+
+  @override
+  String toString() {
+    return 'Item(id: $id, data: $data, createdAt: $createdAt, updatedAt: $updatedAt)';
+  }
+
+  @override
+  bool operator ==(Object other) {
+    if (identical(this, other)) return true;
+    return other is Item &&
+        other.id == id &&
+        other.createdAt == createdAt &&
+        other.updatedAt == updatedAt;
+  }
+
+  @override
+  int get hashCode => id.hashCode ^ createdAt.hashCode ^ updatedAt.hashCode;
+}
+