fix(chat): preserve private send response fields

src/app/chat/components/chat-area.tsx

@@ -2,8 +2,6 @@
 /**
  * ChatArea 消息列表区
  *
- * 原始 Dart: lib/ui/chat/widgets/chat_area.dart（153 行）
- *
  * 组成（自上而下）：
  *   - AI 披露横幅
  *   - 日期分隔条

src/data/dto/chat/chat_send_response.ts

@@ -26,6 +26,9 @@ export class ChatSendResponse {
   declare readonly paywallTriggered: boolean;
   declare readonly showUpgrade: boolean;
   declare readonly imageType: string | null;
+  declare readonly isPrivate: boolean | null;
+  declare readonly privateLocked: boolean | null;
+  declare readonly privateHint: string | null;
   declare readonly imageUrl: string | null;
 
   private constructor(input: ChatSendResponseInput) {

src/data/schemas/chat/chat_send_response.ts

@@ -30,6 +30,9 @@ export const ChatSendResponseSchema = z.object({
   paywallTriggered: z.boolean().default(false),
   showUpgrade: z.boolean().default(false),
   imageType: z.string().nullable().default(null),
+  isPrivate: z.boolean().nullable().default(null),
+  privateLocked: z.boolean().nullable().default(null),
+  privateHint: z.string().nullable().default(null),
   imageUrl: z.string().nullable().default(null),
 });
 

src/stores/chat/chat-machine.actors.ts

@@ -41,8 +41,6 @@ export function getActiveChatWebSocket(): ChatWebSocket | null {
   return activeChatWebSocket;
 }
 
-// 本地游客消息额度 actor 已停用：消息数量限制统一交由后端 blocked/daily_limit 响应处理。
-
 // ============================================================
 // Init 任务 2：拉 history 3 步流（fromPromise，返回最终结果）
 // ============================================================

src/stores/chat/chat-machine.helpers.ts

@@ -89,6 +89,13 @@ export function sendResponseToUiMessage(response: ChatSendResponse): UiMessage {
     ...(response.showUpgrade && response.imageUrl
       ? { imagePaywalled: true }
       : {}),
+    ...(response.isPrivate != null ? { isPrivate: response.isPrivate } : {}),
+    ...(response.privateLocked != null
+      ? { privateLocked: response.privateLocked }
+      : {}),
+    ...(response.privateHint != null
+      ? { privateHint: response.privateHint }
+      : {}),
   };
 }