feat: Enhance account identification to support email, mobile, and token-only synthetic IDs across API, UI, and documentation.

webui/src/locales/en.json

@@ -86,6 +86,7 @@
         "requiredFields": "Password and email/mobile are required.",
         "deleteKeyConfirm": "Are you sure you want to delete this API key?",
         "deleteAccountConfirm": "Are you sure you want to delete this account?",
+        "invalidIdentifier": "Invalid account identifier. Operation aborted.",
         "testAllConfirm": "Test API connectivity for all accounts?",
         "testAllCompleted": "Completed: {success}/{total} available",
         "testFailed": "Test failed: {error}",

webui/src/locales/zh.json

@@ -86,6 +86,7 @@
         "requiredFields": "需要填写密码以及邮箱或手机号",
         "deleteKeyConfirm": "确定要删除此 API 密钥吗？",
         "deleteAccountConfirm": "确定要删除此账号吗？",
+        "invalidIdentifier": "账号标识无效，无法执行操作",
         "testAllConfirm": "测试所有账号的 API 连通性？",
         "testAllCompleted": "完成：{success}/{total} 可用",
         "testFailed": "测试失败: {error}",