fix(i18n): internationalize test script related error messages

Fixed 5 hardcoded Chinese error messages to support bilingual display:

Backend changes (services):
- provider.rs: Fixed 4 error messages:
  * Data format error when deserializing array (line 731)
  * Data format error when deserializing single object (line 738)
  * Regex initialization failure (line 1163)
  * App type not found (line 1191)
- speedtest.rs: Fixed 1 error message:
  * HTTP client creation failure (line 104)

All errors now use AppError::localized to provide both Chinese and English messages.

Impact:
- Users will now see properly localized error messages when testing usage scripts
- Error messages respect the application language setting
- Better user experience for English-speaking users

src-tauri/src/services/speedtest.rs

@@ -101,7 +101,11 @@ impl SpeedtestService {
             .redirect(reqwest::redirect::Policy::limited(5))
             .user_agent("cc-switch-speedtest/1.0")
             .build()
-            .map_err(|e| AppError::Message(format!("创建 HTTP 客户端失败: {e}")))
+            .map_err(|e| AppError::localized(
+                "speedtest.client_create_failed",
+                format!("创建 HTTP 客户端失败: {e}"),
+                format!("Failed to create HTTP client: {e}")
+            ))
     }
 
     fn sanitize_timeout(timeout_secs: Option<u64>) -> u64 {