feat(mp): Day 10 — 小程序会话 API 封装

- sendAiMessage 支持 sessionId 参数
- 新增 createSession / listSessions / renameSession / closeSession
- AiChatSession 接口定义

apps/miniprogram/src/services/ai-chat.ts

@@ -28,6 +28,7 @@ export async function sendAiMessage(
   message: string,
   history?: AiChatMessage[],
   patientId?: string,
+  sessionId?: string,
 ): Promise<AiChatResponse> {
   const body: Record<string, unknown> = {
     message,
@@ -36,10 +37,43 @@ export async function sendAiMessage(
   if (patientId) {
     body.patient_id = patientId;
   }
+  if (sessionId) {
+    body.session_id = sessionId;
+  }
   const resp = await api.post<AiChatResponse>('/ai/chat', body);
   return resp;
 }
 
+// === 会话 API ===
+
+export interface AiChatSession {
+  id: string;
+  title: string | null;
+  patient_id: string | null;
+  status: string;
+  created_at: string;
+  updated_at: string;
+}
+
+export async function createSession(patientId?: string, title?: string): Promise<AiChatSession> {
+  const body: Record<string, unknown> = {};
+  if (patientId) body.patient_id = patientId;
+  if (title) body.title = title;
+  return api.post<AiChatSession>('/ai/chat/sessions', body);
+}
+
+export async function listSessions(): Promise<AiChatSession[]> {
+  return api.get<AiChatSession[]>('/ai/chat/sessions');
+}
+
+export async function renameSession(sessionId: string, title: string): Promise<void> {
+  await api.put(`/ai/chat/sessions/${sessionId}/rename`, { title });
+}
+
+export async function closeSession(sessionId: string): Promise<void> {
+  await api.post(`/ai/chat/sessions/${sessionId}/close`, {});
+}
+
 /** 获取聊天历史（本地缓存） */
 export function getLocalHistory(): AiChatMessage[] {
   try {