feat(proxies): 代理有效期与失败回退

- schema/迁移: 代理有效期、提醒天数、失败回退配置 + 账号 fallback 来源字段
- service/repo/DTO/handler: CRUD 透传新字段 + 校验
- fallback 目标解析纯函数(链式解析 + 环检测 + 兜底)
- SweepExpiredProxies 到期改投账号 + outbox 失效
- ProxyExpiryService 后台到期扫描任务 + wire 注册
- 账号侧手动回切原代理 + fallback 来源徽章/按钮
- 前端: 创建/编辑表单、列表到期徽章、类型/API/i18n
- ops 告警: proxy_expired_count / proxy_expiring_soon_count 指标
- 导入导出携带有效期/回退字段(备用按 name 映射)
- 补全测试 stub + 集成测试 + review 问题修复

frontend/src/api/admin/accounts.ts

@@ -659,6 +659,16 @@ export interface BatchOperationResult {
   warnings?: Array<{ account_id: number; warning: string }>
 }
 
+/**
+ * Revert account proxy to original before fallback
+ * @param id - Account ID
+ * @returns Success confirmation
+ */
+export async function revertProxyFallback(id: number): Promise<{ message: string }> {
+  const { data } = await apiClient.post<{ message: string }>(`/admin/accounts/${id}/revert-proxy-fallback`)
+  return data
+}
+
 /**
  * Batch clear account errors
  * @param accountIds - Array of account IDs
@@ -735,7 +745,8 @@ export const accountsAPI = {
   getAntigravityDefaultModelMapping,
   batchClearError,
   batchRefresh,
-  setPrivacy
+  setPrivacy,
+  revertProxyFallback
 }
 
 export default accountsAPI

frontend/src/api/admin/proxies.ts

@@ -27,7 +27,7 @@ export async function list(
   pageSize: number = 20,
   filters?: {
     protocol?: string
-    status?: 'active' | 'inactive'
+    status?: 'active' | 'inactive' | 'expired'
     search?: string
     sort_by?: string
     sort_order?: 'asc' | 'desc'
@@ -227,7 +227,7 @@ export async function exportData(options?: {
   ids?: number[]
   filters?: {
     protocol?: string
-    status?: 'active' | 'inactive'
+    status?: 'active' | 'inactive' | 'expired'
     search?: string
     sort_by?: string
     sort_order?: 'asc' | 'desc'