refactor: optimize scene prompt formatting and selection sync logic

packages/derisk-serve/src/derisk_serve/agent/agents/chat/agent_chat.py

@@ -1137,11 +1137,12 @@ async def _load_and_inject_scenes(
             return ""
 
         # 构建场景提示词
+        scene_separator = "\n\n---\n\n"
         scene_prompt = f"""# 场景定义
 
 你是根据以下场景定义来协助用户的智能助手。请严格遵循场景定义中的角色设定、工作流程和工具使用规范。
 
-{"\n\n---\n\n".join(scene_contents)}
+{scene_separator.join(scene_contents)}
 
 ---
 

web/src/app/application/app/components/tab-scenes.tsx

@@ -200,8 +200,14 @@ export default function TabScenes() {
 
   // 从 appInfo 中获取已选择的场景
   useEffect(() => {
-    if (appInfo?.scenes) {
-      setSelectedScenes(appInfo.scenes);
+    if (appInfo?.scenes && appInfo.scenes.length > 0) {
+      const serverHasNewScenes = appInfo.scenes.some(id => !selectedScenes.includes(id));
+      const localHasUnsyncedScenes = selectedScenes.some(id => !appInfo.scenes.includes(id));
+      const isInitializing = selectedScenes.length === 0;
+
+      if (serverHasNewScenes || (isInitializing && !localHasUnsyncedScenes)) {
+        setSelectedScenes(appInfo.scenes);
+      }
     }
   }, [appInfo?.scenes]);
 
@@ -338,10 +344,12 @@ export default function TabScenes() {
 
       const newScenes = [...selectedScenes, newScene.scene_id];
       setSelectedScenes(newScenes);
+
       await fetchUpdateApp({ ...appInfo, scenes: newScenes });
 
       message.success(t('scene_create_success', '场景创建成功'));
       setCreateModalVisible(false);
+
       setActiveSceneId(newScene.scene_id);
       setEditingContent(defaultContent);
       setHasChanges(false);