新增小程序后端代码，包括数据库、路由、服务层等。

小程序前后端打通，包括登录、注册、绑定设备、查询绑定信息，修改小朋友名称等功能。

banban-mini/src/services/api.ts

@@ -0,0 +1,56 @@
+import Taro from '@tarojs/taro'
+
+// const BASE_URL = 'http://175.24.73.253:8001' // 改为实际后端IP
+const BASE_URL = 'http://127.0.0.1:8001' 
+
+class ApiError extends Error {
+  constructor(public status: number, message: string) {
+    super(message)
+  }
+}
+
+async function request<T>(
+  url: string,
+  options: {
+    method?: 'GET' | 'POST' | 'PUT' | 'PATCH' | 'DELETE'
+    data?: any
+    headers?: Record<string, string>
+  } = {}
+): Promise<T> {
+  const token = Taro.getStorageSync('token')
+  console.log(`[API] ${options.method || 'GET'} ${url}`, token ? 'with token' : 'no token')
+  
+  const headers: Record<string, string> = {
+    'Content-Type': 'application/json',
+    ...options.headers,
+  }
+  if (token) {
+    headers['Authorization'] = `Bearer ${token}`
+  }
+
+  const response = await Taro.request({
+    url: `${BASE_URL}${url}`,
+    method: options.method || 'GET',
+    data: options.data,
+    header: headers,
+  })
+
+  console.log(`[API] Response status:`, response.statusCode)
+  
+  if (response.statusCode >= 400) {
+    const detail = response.data?.detail || 'Request failed'
+    throw new ApiError(response.statusCode, detail)
+  }
+
+  return response.data
+}
+
+export { request, ApiError, BASE_URL }
+
+export function getToken(): string {
+  return Taro.getStorageSync('token') || ''
+}
+
+export function getCurrentUserId(): number {
+  return Taro.getStorageSync('user_id') || 0
+}