feat: 接通 Planner → Action → Validator

app/actions/registry.py

@@ -2,6 +2,7 @@
 
 from typing import Any
 
+from app.actions.add import AddHandler
 from app.actions.base import BaseActionHandler
 from app.actions.move import MoveHandler
 from app.actions.resize import ResizeHandler
@@ -11,6 +12,7 @@ from app.schemas.screen import Screen
 
 # 新增操作时在此注册，未实现的操作明确报错
 ACTION_HANDLERS: dict[str, BaseActionHandler[Any]] = {
+    "add": AddHandler(),
     "move": MoveHandler(),
     "resize": ResizeHandler(),
     "update": UpdateHandler(),