fix: optimize compliance scan performance and improve error handling

- Refactor scan_compliance to eliminate N+1 queries using joinedload and batch loading
- Add try-except wrapper in compliance scan API endpoint
- Improve frontend axios error interceptor to display detail/message/timeout errors
- Update CORS config and nginx for domain deployment

backend/app/api/v1/compliance.py

@@ -1,5 +1,5 @@
 from typing import Optional
-from fastapi import APIRouter, Depends, Query
+from fastapi import APIRouter, Depends, Query, HTTPException, status
 from sqlalchemy.orm import Session
 
 from app.core.database import get_db
@@ -26,8 +26,16 @@ def scan_compliance(
     db: Session = Depends(get_db),
     current_user: User = Depends(get_current_user),
 ):
-    issues = compliance_service.scan_compliance(db, project_id=project_id)
-    return ResponseModel(data={"issues_found": len(issues)})
+    try:
+        issues = compliance_service.scan_compliance(db, project_id=project_id)
+        return ResponseModel(data={"issues_found": len(issues)})
+    except Exception:
+        import logging
+        logging.exception("Compliance scan failed")
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail="扫描执行失败，请稍后重试"
+        )
 
 
 @router.get("/issues")
@@ -67,6 +75,5 @@ def resolve_issue(
 ):
     issue = compliance_service.resolve_issue(db, issue_id)
     if not issue:
-        from fastapi import HTTPException, status
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="问题不存在")
     return ResponseModel(message="已标记为已解决")