feat(web): Day 9 — Web ChatPage + 会话 API 前端

- ChatPage 组件: 左侧会话列表(260px) + 右侧聊天区 + RichMessage 富消息
- 新建/选择/重命名/关闭会话，session_id 模式消息持久化
- aiChatApi 新增 createSession/listSessions/renameSession/closeSession
- 路由 /ai/chat 注册，支持 display_hints 富消息渲染
- App.tsx 路由权限校验覆盖

apps/web/src/api/ai/chat.ts

@@ -54,17 +54,55 @@ export interface ChatResponse {
   display_hints?: DisplayHint[];
 }
 
+export interface ChatSession {
+  id: string;
+  title: string | null;
+  patient_id: string | null;
+  status: string;
+  created_at: string;
+  updated_at: string;
+}
+
 export const aiChatApi = {
   sendMessage: async (
     message: string,
     history: ChatHistoryItem[],
-    patientId?: string
+    patientId?: string,
+    sessionId?: string
   ): Promise<ChatResponse> => {
     const resp = await client.post('/ai/chat', {
       message,
       history,
       ...(patientId ? { patient_id: patientId } : {}),
+      ...(sessionId ? { session_id: sessionId } : {}),
     });
     return resp.data.data as ChatResponse;
   },
+
+  createSession: async (
+    patientId?: string,
+    title?: string
+  ): Promise<ChatSession> => {
+    const resp = await client.post('/ai/chat/sessions', {
+      ...(patientId ? { patient_id: patientId } : {}),
+      ...(title ? { title } : {}),
+    });
+    return resp.data.data as ChatSession;
+  },
+
+  listSessions: async (): Promise<ChatSession[]> => {
+    const resp = await client.get('/ai/chat/sessions');
+    return resp.data.data as ChatSession[];
+  },
+
+  renameSession: async (
+    sessionId: string,
+    title: string
+  ): Promise<void> => {
+    await client.put(`/ai/chat/sessions/${sessionId}/rename`, { title });
+  },
+
+  closeSession: async (sessionId: string): Promise<void> => {
+    await client.post(`/ai/chat/sessions/${sessionId}/close`);
+  },
 };