feat: 完善联网搜索功能集成到React模式

backend/app/main_graph/nodes/react_nodes.py

@@ -88,7 +88,61 @@ def react_reason_node(state: MainGraphState) -> MainGraphState:
     return state
 
 
-# ========== 2. 错误处理节点 ==========
+# ========== 2. 联网搜索节点 ==========
+
+def web_search_node(state: MainGraphState) -> MainGraphState:
+    """
+    联网搜索节点：执行搜索并将结果保存到状态
+    """
+    state.current_phase = "web_searching"
+    
+    # 获取搜索查询
+    reasoning_result = state.debug_info.get("reasoning_result")
+    search_query = reasoning_result.metadata.get("search_query", state.user_query) if reasoning_result else state.user_query
+    
+    try:
+        from app.core import web_search
+        
+        print(f"[WebSearch] 搜索: {search_query}")
+        search_result = web_search(search_query, max_results=5)
+        
+        # 保存搜索结果到状态
+        if not hasattr(state, "web_search_results"):
+            state.web_search_results = []
+        state.web_search_results.append(search_result)
+        
+        # 将搜索结果添加到 rag_context，供 LLM 使用
+        if state.rag_context:
+            state.rag_context = f"{state.rag_context}\n\n---\n\n## 🌐 联网搜索结果:\n{search_result}"
+        else:
+            state.rag_context = f"## 🌐 联网搜索结果:\n{search_result}"
+        
+        state.success = True
+        print(f"[WebSearch] 搜索完成")
+        
+    except Exception as e:
+        from app.main_graph.state import ErrorRecord, ErrorSeverity
+        from datetime import datetime
+        
+        error_record = ErrorRecord(
+            error_type="WebSearchError",
+            error_message=str(e),
+            severity=ErrorSeverity.WARNING,
+            source="web_search_node",
+            timestamp=datetime.now().isoformat(),
+            retry_count=0,
+            max_retries=2,
+            context={"search_query": search_query}
+        )
+        state.errors.append(error_record)
+        state.current_error = error_record
+        state.current_phase = "error_handling"
+        state.success = False
+    
+    return state
+
+
+# ========== 3. 错误处理节点 ==========
 
 def error_handling_node(state: MainGraphState) -> MainGraphState:
     """
@@ -276,6 +330,7 @@ def route_by_reasoning(state: MainGraphState) -> str:
         "direct_response": "final_response",
         "retrieve_rag": "rag_retrieve",
         "re_retrieve_rag": "rag_retrieve",
+        "web_search": "web_search",  # ⭐ 新增：联网搜索
         "clarify": "final_response",
         "call_tool": "final_response",  # 暂时映射到 final_response，后续可以扩展
         "contact": "contact_subgraph",
@@ -291,6 +346,7 @@ def route_by_reasoning(state: MainGraphState) -> str:
 __all__ = [
     "init_state_node",
     "react_reason_node",
+    "web_search_node",  # ⭐ 新增
     "error_handling_node",
     "final_response_node",
     "route_by_reasoning"