feat: 完成后端处理链路、优化部分提示词

app/actions/delete.py

@@ -0,0 +1,12 @@
+"""在大屏 JSON 副本上删除组件，用于后端校验，不删除共享数据源"""
+
+from app.actions.base import BaseActionHandler
+from app.schemas.actions import DeleteAction
+from app.schemas.screen import Screen
+
+
+class DeleteHandler(BaseActionHandler[DeleteAction]):
+    def apply(self, screen: Screen, action: DeleteAction) -> Screen:
+        result, target = self.copy_target(screen, action.target_id)
+        result.nodes = [node for node in result.nodes if node.id != target.id]
+        return result