feat: 新增需求理解并实现human in loop

app/processor/nodes/wait_for_user_node.py

@@ -0,0 +1,38 @@
+"""暂停图并接收用户回答，不在恢复时重复调用模型"""
+
+from langgraph.types import interrupt
+from pydantic import ValidationError
+
+from app.processor.base import BaseNode
+from app.processor.state import QueryState
+from app.schemas.clarification_reply import ClarificationReply
+
+
+class WaitForUserNode(BaseNode):
+    name = "wait_for_user_node"
+
+    def process(self, state: QueryState) -> QueryState:
+        payload = state["clarification"].model_dump(mode="json")
+        while True:
+            # interrupt 的控制异常必须交给 LangGraph 处理
+            value = interrupt(payload)
+            try:
+                reply = ClarificationReply.model_validate(
+                    {"answer": value} if isinstance(value, str) else value
+                )
+                if not reply.cancel and reply.option_id is not None:
+                    if reply.option_id not in {
+                        option.id for option in state["clarification"].options
+                    }:
+                        raise ValueError("无效选项")
+                break
+            except (ValidationError, ValueError):
+                payload = {
+                    **payload,
+                    "error": "请选择本题有效选项或填写回答，并提供有效的大屏数据；也可设置 cancel=true 取消",
+                }
+        return {
+            **state,
+            "clarification_reply": reply,
+            "status": "cancelled" if reply.cancel else "running",
+        }