feat: enhance agent orchestration, knowledge flow and UI refinements

backend/app/routers/todo.py

@@ -1,7 +1,8 @@
+from datetime import UTC, date, datetime
+
 from fastapi import APIRouter, Depends, HTTPException, Query
+from sqlalchemy import func, select
 from sqlalchemy.ext.asyncio import AsyncSession
-from sqlalchemy import select, func
-from datetime import date
 from app.database import get_db
 from app.models.todo import DailyTodo, TodoSource
 from app.models.user import User
@@ -52,7 +53,7 @@ async def create_todo(
         user_id=current_user.id,
         title=data.title,
         source=TodoSource.MANUAL,
-        todo_date=date.today().isoformat(),
+        todo_date=(data.todo_date or date.today()).isoformat(),
     )
     db.add(todo)
     await db.commit()
@@ -74,14 +75,11 @@ async def update_todo(
     if not todo:
         raise HTTPException(status_code=404, detail="待办不存在")
 
-    # 历史日期不允许修改
-    if todo.todo_date != date.today().isoformat():
-        raise HTTPException(status_code=403, detail="历史待办不可修改")
-
     if data.title is not None:
         todo.title = data.title
+    if data.todo_date is not None:
+        todo.todo_date = data.todo_date.isoformat()
     if data.is_completed is not None:
-        from datetime import UTC, datetime
         todo.is_completed = data.is_completed
         todo.completed_at = datetime.now(UTC) if data.is_completed else None
 
@@ -102,9 +100,6 @@ async def delete_todo(
     todo = result.scalar_one_or_none()
     if not todo:
         raise HTTPException(status_code=404, detail="待办不存在")
-    if todo.todo_date != date.today().isoformat():
-        raise HTTPException(status_code=403, detail="历史待办不可删除")
-
     await db.delete(todo)
     await db.commit()