feat: 完善子图，添加路由函数和审核节点

backend/app/agent_subgraphs/news_analysis/nodes.py

@@ -164,5 +164,22 @@ def format_result(state: NewsAnalysisState) -> NewsAnalysisState:
     state.final_result = "\n".join(output_lines)
     state.success = True
     state.current_phase = "completed"
-    
+
     return state
+
+
+def should_continue(state: NewsAnalysisState) -> str:
+    """
+    条件路由函数：根据 action 决定下一个节点
+    """
+    action = state.action
+    if action == NewsAction.QUERY:
+        return "query_news"
+    elif action == NewsAction.ANALYZE_URL:
+        return "analyze_url"
+    elif action == NewsAction.EXTRACT_KEYWORDS:
+        return "extract_keywords"
+    elif action == NewsAction.GENERATE_REPORT:
+        return "generate_report"
+    else:
+        return "format_result"