chore: initial release

lib/core/models/conversation.dart

@@ -0,0 +1,27 @@
+import 'package:freezed_annotation/freezed_annotation.dart';
+import 'chat_message.dart';
+
+part 'conversation.freezed.dart';
+part 'conversation.g.dart';
+
+@freezed
+sealed class Conversation with _$Conversation {
+  const factory Conversation({
+    required String id,
+    required String title,
+    required DateTime createdAt,
+    required DateTime updatedAt,
+    String? model,
+    String? systemPrompt,
+    @Default([]) List<ChatMessage> messages,
+    @Default({}) Map<String, dynamic> metadata,
+    @Default(false) bool pinned,
+    @Default(false) bool archived,
+    String? shareId,
+    String? folderId,
+    @Default([]) List<String> tags,
+  }) = _Conversation;
+
+  factory Conversation.fromJson(Map<String, dynamic> json) =>
+      _$ConversationFromJson(json);
+}