docs: 添加 AG-UI 协议规则约束到 apps/AGENTS.md

apps/lib/features/chat/data/models/ag_ui_event.dart

@@ -61,6 +61,7 @@ const _typeToWireMap = {
   AgUiEventType.toolCallEnd: AgUiEventTypeWire.toolCallEnd,
   AgUiEventType.toolCallResult: AgUiEventTypeWire.toolCallResult,
   AgUiEventType.toolCallError: AgUiEventTypeWire.toolCallError,
+  AgUiEventType.messagesSnapshot: AgUiEventTypeWire.messagesSnapshot,
   AgUiEventType.unknown: '',
 };
 
@@ -102,6 +103,8 @@ class AgUiEvent {
         return ToolCallResultEvent.fromJson(json);
       case AgUiEventType.toolCallError:
         return ToolCallErrorEvent.fromJson(json);
+      case AgUiEventType.messagesSnapshot:
+        return MessagesSnapshotEvent.fromJson(json);
       case AgUiEventType.unknown:
         return UnknownAgUiEvent.fromJson(json);
     }
@@ -297,3 +300,39 @@ class ToolCallErrorEvent extends AgUiEvent {
   @override
   Map<String, dynamic> toJson() => _$ToolCallErrorEventToJson(this);
 }
+
+@JsonSerializable()
+class MessagesSnapshotEvent extends AgUiEvent {
+  final List<SnapshotMessage> messages;
+
+  MessagesSnapshotEvent({required this.messages})
+    : super(type: AgUiEventType.messagesSnapshot);
+
+  factory MessagesSnapshotEvent.fromJson(Map<String, dynamic> json) =>
+      _$MessagesSnapshotEventFromJson(json);
+
+  @override
+  Map<String, dynamic> toJson() => _$MessagesSnapshotEventToJson(this);
+}
+
+@JsonSerializable()
+class SnapshotMessage {
+  final String id;
+  final String role;
+  final String? content;
+  final String? toolCallId;
+  final UiCard? ui;
+
+  SnapshotMessage({
+    required this.id,
+    required this.role,
+    this.content,
+    this.toolCallId,
+    this.ui,
+  });
+
+  factory SnapshotMessage.fromJson(Map<String, dynamic> json) =>
+      _$SnapshotMessageFromJson(json);
+
+  Map<String, dynamic> toJson() => _$SnapshotMessageToJson(this);
+}