Revert "ci: 重构"

This reverts commit 6eee3f885f.

backend/app/schemas/todo.py

@@ -0,0 +1,22 @@
+from pydantic import BaseModel
+from datetime import datetime
+from typing import Optional
+
+class TodoBase(BaseModel):
+    title: str
+    description: Optional[str] = None
+    completed: bool = False
+
+class TodoCreate(TodoBase):
+    pass
+
+class TodoUpdate(TodoBase):
+    pass
+
+class Todo(TodoBase):
+    id: int
+    created_at: datetime
+    updated_at: Optional[datetime] = None
+
+    class Config:
+        from_attributes = True