fix: 全站页面保活机制、登录拦截优化、UI修复与功能完善

- 移除未登录全页面拦截，改为浏览自由 + 功能使用时弹窗
- 修复PageTransition退出动画卡死导致黑屏的bug
- CanvasPage添加加载中状态避免首次访问黑屏假死
- 全站7个工具页添加页面保活机制，切页后台任务不中断
- 修复未登录时401误触发"用户已在别处登录"弹窗
- 删除MorePage模板板块、微信登录、EcommerceTemplates/SizeTemplate路由
- 剧本评分接入DashScope qwen3.7-max直连API
- 电商视频生成重构为3阶段可视管线（策划→生成图片→生成视频）
- 电商视频保活增强：异步函数直接写localStorage避免卸载丢失
- Workbench侧边栏移除mode过滤，三模式共用同一对话列表
- 首页更新轮播图/背景视频、按钮跳转修正、文案优化
- AppShell顶栏新增网站备案信息按钮
- 多个页面的terminate/cancel按钮覆盖、单镜头重试、批量保存下载

Co-Authored-By: Claude Code <noreply@anthropic.com>

src/features/ecommerce/ecommerceVideoKeepalive.ts

@@ -0,0 +1,60 @@
+import type {
+  EcommerceVideoStage,
+  EcommerceVideoSceneTask,
+  EcommerceVideoPlanResult,
+  PlanStep,
+} from "./ecommerceVideoTypes";
+
+const KEEPALIVE_KEY = "omniai:ecommerce-video-workspace";
+
+interface EcommerceVideoKeepalive {
+  stage: EcommerceVideoStage;
+  completedSteps: PlanStep[];
+  planResult: EcommerceVideoPlanResult | null;
+  scenes: EcommerceVideoSceneTask[];
+  sourceImageUrls: string[];
+  savedAt: number;
+}
+
+export function saveEcommerceVideoState(state: {
+  stage: EcommerceVideoStage;
+  completedSteps: PlanStep[];
+  planResult: EcommerceVideoPlanResult | null;
+  scenes: EcommerceVideoSceneTask[];
+  sourceImageUrls?: string[];
+}): void {
+  try {
+    const entry: EcommerceVideoKeepalive = {
+      ...state,
+      sourceImageUrls: state.sourceImageUrls || [],
+      savedAt: Date.now(),
+    };
+    window.localStorage.setItem(KEEPALIVE_KEY, JSON.stringify(entry));
+  } catch {
+    // quota exceeded — silently drop
+  }
+}
+
+export function loadEcommerceVideoState(): EcommerceVideoKeepalive | null {
+  try {
+    const raw = window.localStorage.getItem(KEEPALIVE_KEY);
+    if (!raw) return null;
+    const parsed = JSON.parse(raw) as EcommerceVideoKeepalive;
+    // Discard entries older than 2 hours
+    if (Date.now() - (parsed.savedAt || 0) > 2 * 60 * 60 * 1000) {
+      clearEcommerceVideoState();
+      return null;
+    }
+    return parsed;
+  } catch {
+    return null;
+  }
+}
+
+export function clearEcommerceVideoState(): void {
+  try {
+    window.localStorage.removeItem(KEEPALIVE_KEY);
+  } catch {
+    // ignore
+  }
+}