feat: add custom task recurrence options

backend/main.py

@@ -468,7 +468,12 @@ async def create_task(
         )
         if parent is None:
             raise HTTPException(status_code=400, detail="父任务必须是同一清单的顶层任务")
-    data = payload.model_dump()
+    if payload.rrule:
+        if not payload.due_at:
+            raise HTTPException(status_code=422, detail="重复任务需要截止时间")
+        from .mvp import parse_rrule
+        parse_rrule(payload.rrule)
+    data = payload.model_dump(exclude={"rrule"})
     parent_filter = Task.parent_id == payload.parent_id if payload.parent_id else Task.parent_id.is_(None)
     max_position = await db.scalar(select(func.max(Task.position)).where(
         Task.user_id == user.id,
@@ -479,6 +484,8 @@ async def create_task(
     task = Task(user_id=user.id, position=(max_position if max_position is not None else -1) + 1, **data)
     db.add(task)
     await db.flush()
+    if payload.rrule:
+        db.add(RecurrenceTemplate(user_id=user.id, task_id=task.id, rrule=payload.rrule.upper(), starts_at=task.due_at))
     audit(db, user.id, "create", "task", task.id)
     await db.commit()
     await db.refresh(task)

backend/schemas.py

@@ -77,6 +77,7 @@ class TaskCreate(BaseModel):
     priority: int = Field(default=0, ge=0, le=3)
     due_at: datetime | None = None
     parent_id: UUID | None = None
+    rrule: str | None = Field(default=None, min_length=5, max_length=1000)
 
 
 class TaskUpdate(BaseModel):