feat(ui): OpenAI OAuth 账号支持批量 RT 输入创建

新增通过手动输入 Refresh Token 创建 OpenAI OAuth 账号功能，
参考 Anthropic sessionKey 批量创建方式：

- useOpenAIOAuth 添加 validateRefreshToken 方法
- accounts.ts 添加 refreshOpenAIToken API
- AuthInputMethod 类型新增 refresh_token 选项
- 支持多行输入 RT（每行一个）批量创建账号
- 账号名称自动累加后缀 #1, #2 等
- UI 显示 RT 数量徽章和批量创建提示
- 添加中英文 i18n 翻译

frontend/src/api/admin/accounts.ts

@@ -398,6 +398,26 @@ export async function getAntigravityDefaultModelMapping(): Promise<Record<string
   return data
 }
 
+/**
+ * Refresh OpenAI token using refresh token
+ * @param refreshToken - The refresh token
+ * @param proxyId - Optional proxy ID
+ * @returns Token information including access_token, email, etc.
+ */
+export async function refreshOpenAIToken(
+  refreshToken: string,
+  proxyId?: number | null
+): Promise<Record<string, unknown>> {
+  const payload: { refresh_token: string; proxy_id?: number } = {
+    refresh_token: refreshToken
+  }
+  if (proxyId) {
+    payload.proxy_id = proxyId
+  }
+  const { data } = await apiClient.post<Record<string, unknown>>('/admin/openai/refresh-token', payload)
+  return data
+}
+
 export const accountsAPI = {
   list,
   getById,
@@ -418,6 +438,7 @@ export const accountsAPI = {
   getAvailableModels,
   generateAuthUrl,
   exchangeCode,
+  refreshOpenAIToken,
   batchCreate,
   batchUpdateCredentials,
   bulkUpdate,