feat: migrate from Element Plus to Ant Design Vue and update Vite configuration for better dependency management

- Updated Vite configuration to manually chunk Ant Design Vue for improved dependency management.
- Added a comprehensive migration testing checklist for transitioning from Element Plus 2.13.0 to Ant Design Vue 4.x, covering various components and functionalities.

backend/api/tasks.py

@@ -2,6 +2,7 @@ from fastapi import APIRouter, Depends, HTTPException, status
 from sqlalchemy.orm import Session
 from typing import List
 from datetime import datetime, timedelta
+from pydantic import BaseModel, Field
 
 from backend.models import get_db, User
 from backend.schemas.task import TaskCreate, TaskUpdate, TaskResponse
@@ -11,6 +12,11 @@ from backend.dependencies import get_current_user
 router = APIRouter()
 
 
+class CronValidateRequest(BaseModel):
+    """Cron 表达式验证请求"""
+    cron_expression: str = Field(..., min_length=9, description="Crontab 表达式")
+
+
 @router.post("/", response_model=TaskResponse, status_code=status.HTTP_201_CREATED, summary="创建打卡任务")
 async def create_task(
     task_data: TaskCreate,
@@ -181,7 +187,7 @@ async def toggle_task(
 
 
 @router.post("/validate-cron", summary="验证 Crontab 表达式")
-async def validate_cron_expression(request: dict):
+async def validate_cron_expression(request: CronValidateRequest):
     """
     验证 Crontab 表达式并预览下一个执行时间
 
@@ -199,7 +205,7 @@ async def validate_cron_expression(request: dict):
         "description": "每天 20:00"
     }
     """
-    cron_expr = request.get('cron_expression', '').strip()
+    cron_expr = request.cron_expression.strip()
 
     if not cron_expr:
         raise HTTPException(