feat: 添加云端函数HTTP请求、SMTP邮件、数据库操作能力

- 添加HTTP客户端工具支持GET/POST请求
- 添加SMTP邮件发送功能
- 添加数据库操作(db.getRecords, db.deleteRecord, db.deleteRecords)
- 添加订单管理云端函数(读取、接收、筛选、成功、失败)
- 添加测试推送和邮件通知云端函数
- 修复云端函数编辑页面预览代码换行显示
- 云端变量数据模型重构(合并数据类型)

frontend/src/pages/agent/cards/create.vue

@@ -19,7 +19,7 @@ const form = ref({
   quantity: 1,
 })
 
-const selectedApp = computed(() => {
+const _selectedApp = computed(() => {
   return apps.value.find(a => a.id === Number(form.value.app_id))
 })
 
@@ -34,11 +34,11 @@ const totalPrice = computed(() => {
 
 onMounted(async () => {
   try {
-    const data = await api.get('/agent/apps')
+    const data = await api.get<any[]>('/agent/apps')
     apps.value = data || []
 
     if (apps.value.length > 0) {
-      const typesData = await api.get('/agent/card-types')
+      const typesData = await api.get<any[]>('/agent/card-types')
       cardTypes.value = typesData || []
     }
   }

frontend/src/pages/agent/cards/index.vue

@@ -30,7 +30,7 @@ onMounted(async () => {
   }
 })
 
-function formatDate(dateStr: string) {
+function formatDate(dateStr: string | null) {
   if (!dateStr)
     return '-'
   return new Date(dateStr).toLocaleDateString('zh-CN')