fix(editor): 片段同步失败加提示 + 删除片段加二次确认

- syncClipsToBackend 失败时提示用户，不再静默吞错
- 删除片段统一走 Modal.confirm 二次确认（时间轴✕按钮/右键菜单/顶栏退格/片段列表 4处入口全部生效）

apps/web/src/pages/editing-planner/EditingPlanner.tsx

@@ -622,8 +622,17 @@ const EditingPlanner: React.FC = () => {
   };
 
   const handleClipRemove = (clipId: string) => {
-    setClips((prev) => prev.filter((c) => c.id !== clipId));
-    if (selectedClipId === clipId) setSelectedClipId(null);
+    Modal.confirm({
+      title: "删除片段",
+      content: "确定要删除这个片段吗？此操作可通过撤销恢复。",
+      okText: "删除",
+      okType: "danger",
+      cancelText: "取消",
+      onOk: () => {
+        setClips((prev) => prev.filter((c) => c.id !== clipId));
+        if (selectedClipId === clipId) setSelectedClipId(null);
+      },
+    });
   };
 
   const handleClipUpdate = useCallback(
@@ -1009,17 +1018,13 @@ const EditingPlanner: React.FC = () => {
   const syncClipsToBackend = async (planId: string): Promise<void> => {
     if (clips.length === 0) return;
 
-    // 1. 获取后端现有片段 ID
-    try {
-      const existing = await getEditPlanClips(planId, { limit: 500 });
-      if (existing.items.length > 0) {
-        await batchDeleteEditPlanClips(
-          planId,
-          existing.items.map((c) => c.id),
-        );
-      }
-    } catch (err) {
-      console.warn("[获取后端片段失败，跳过删除]", err);
+    // 1. 获取并删除后端现有片段
+    const existing = await getEditPlanClips(planId, { limit: 500 });
+    if (existing.items.length > 0) {
+      await batchDeleteEditPlanClips(
+        planId,
+        existing.items.map((c) => c.id),
+      );
     }
 
     // 2. 批量创建新片段（并发 3 个）
@@ -1118,6 +1123,7 @@ const EditingPlanner: React.FC = () => {
         await syncClipsToBackend(planId);
       } catch (syncErr) {
         console.warn("[片段同步失败]", syncErr);
+        message.warning("片段同步失败，将使用模板默认配置生成");
         // 同步失败不阻塞生成，后端有模板兜底
       }