fix: 修复 certificate/dashboard API 的 get_db 导入路径

backend/app/api/v1/endpoints/dashboard.py

@@ -8,7 +8,7 @@ from typing import Optional
 from fastapi import APIRouter, Depends, HTTPException, status, Query
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from app.core.database import get_db
+from app.core.deps import get_db
 from app.core.security import get_current_user
 from app.models.user import User
 from app.services.dashboard_service import DashboardService