feat(usage-query): decouple credentials from provider config

Add independent credential fields for usage query to support different
query endpoints and authentication methods.

Changes:
- Add `apiKey` and `baseUrl` fields to UsageScript struct
- Remove dependency on provider config credentials in query_usage
- Update test_usage_script to accept independent credential parameters
- Add credential input fields in UsageScriptModal based on template:
  * General: apiKey + baseUrl
  * NewAPI: baseUrl + accessToken + userId
  * Custom: no additional fields (full freedom)
- Auto-clear irrelevant fields when switching templates
- Add i18n text for "credentialsConfig"

Benefits:
- Query API can use different endpoint/key than provider config
- Better separation of concerns
- More flexible for various usage query scenarios

src-tauri/src/commands/provider.rs

@@ -123,6 +123,7 @@ pub async fn queryProviderUsage(
 
 /// 测试用量脚本（使用当前编辑器中的脚本，不保存）
 #[allow(non_snake_case)]
+#[allow(clippy::too_many_arguments)]
 #[tauri::command]
 pub async fn testUsageScript(
     state: State<'_, AppState>,
@@ -130,6 +131,8 @@ pub async fn testUsageScript(
     app: String,
     #[allow(non_snake_case)] scriptCode: String,
     timeout: Option<u64>,
+    #[allow(non_snake_case)] apiKey: Option<String>,
+    #[allow(non_snake_case)] baseUrl: Option<String>,
     #[allow(non_snake_case)] accessToken: Option<String>,
     #[allow(non_snake_case)] userId: Option<String>,
 ) -> Result<crate::provider::UsageResult, String> {
@@ -140,6 +143,8 @@ pub async fn testUsageScript(
         &providerId,
         &scriptCode,
         timeout.unwrap_or(10),
+        apiKey.as_deref(),
+        baseUrl.as_deref(),
         accessToken.as_deref(),
         userId.as_deref(),
     )