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/provider.rs

@@ -728,10 +728,18 @@ impl ProviderService {
             Ok(data) => {
                 let usage_list: Vec<UsageData> = if data.is_array() {
                     serde_json::from_value(data)
-                        .map_err(|e| AppError::Message(format!("数据格式错误: {}", e)))?
+                        .map_err(|e| AppError::localized(
+                            "usage_script.data_format_error",
+                            format!("数据格式错误: {}", e),
+                            format!("Data format error: {}", e)
+                        ))?
                 } else {
                     let single: UsageData = serde_json::from_value(data)
-                        .map_err(|e| AppError::Message(format!("数据格式错误: {}", e)))?;
+                        .map_err(|e| AppError::localized(
+                            "usage_script.data_format_error",
+                            format!("数据格式错误: {}", e),
+                            format!("Data format error: {}", e)
+                        ))?;
                     vec![single]
                 };
 
@@ -1152,7 +1160,11 @@ impl ProviderService {
 
                 let base_url = if config_toml.contains("base_url") {
                     let re = Regex::new(r#"base_url\s*=\s*["']([^"']+)["']"#)
-                        .map_err(|e| AppError::Message(format!("正则初始化失败: {}", e)))?;
+                        .map_err(|e| AppError::localized(
+                            "provider.regex_init_failed",
+                            format!("正则初始化失败: {}", e),
+                            format!("Failed to initialize regex: {}", e)
+                        ))?;
                     re.captures(config_toml)
                         .and_then(|caps| caps.get(1))
                         .map(|m| m.as_str().to_string())
@@ -1177,7 +1189,11 @@ impl ProviderService {
     }
 
     fn app_not_found(app_type: &AppType) -> AppError {
-        AppError::Message(format!("应用类型不存在: {:?}", app_type))
+        AppError::localized(
+            "provider.app_not_found",
+            format!("应用类型不存在: {:?}", app_type),
+            format!("App type not found: {:?}", app_type)
+        )
     }
 
     fn now_millis() -> i64 {

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 {