fix: 把完整消息拆成单个字符模拟流式输出

backend/app/agent/agent_service.py

@@ -189,12 +189,26 @@ class AIAgentService:
                     }
         # 处理普通 token
         elif token_content:
-            yield {
+            # 如果内容较长，拆成单个字符模拟流式效果
-                "type": "llm_token",
+            if len(token_content) > 1:
-                "node": node_name,
+                import asyncio
-                "token": token_content,
+                for char in token_content:
-                "reasoning_token": reasoning_token
+                    yield {
-            }
+                        "type": "llm_token",
+                        "node": node_name,
+                        "token": char,
+                        "reasoning_token": reasoning_token
+                    }
+                    # 短暂暂停，模拟打字效果
+                    await asyncio.sleep(0.01)
+            else:
+                # 内容较短，直接发送
+                yield {
+                    "type": "llm_token",
+                    "node": node_name,
+                    "token": token_content,
+                    "reasoning_token": reasoning_token
+                }
 
         # 返回更新后的 current_node
         yield {"type": "_update_state", "current_node": new_current_node}