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/stores/useProjectStore.ts

@@ -1,10 +1,11 @@
 import { create } from 'zustand';
 import type { WebProjectSummary, WebCanvasWorkflow } from '../types';
+import { createBlankWorkflow } from '../data/workflows';
 
 interface ProjectState {
   projects: WebProjectSummary[];
   projectsLoaded: boolean;
-  canvasWorkflow: WebCanvasWorkflow | null;
+  canvasWorkflow: WebCanvasWorkflow;
   currentCanvasProjectId: string | null;
   pendingDeleteProject: WebProjectSummary | null;
   deleteProjectSubmitting: boolean;
@@ -13,7 +14,7 @@ interface ProjectState {
 interface ProjectActions {
   setProjects: (projects: WebProjectSummary[]) => void;
   setProjectsLoaded: (loaded: boolean) => void;
-  setCanvasWorkflow: (workflow: WebCanvasWorkflow | null) => void;
+  setCanvasWorkflow: (workflow: WebCanvasWorkflow) => void;
   setCurrentCanvasProjectId: (id: string | null) => void;
   openDeleteProject: (project: WebProjectSummary) => void;
   closeDeleteProject: () => void;
@@ -24,7 +25,7 @@ interface ProjectActions {
 const initialState: ProjectState = {
   projects: [],
   projectsLoaded: false,
-  canvasWorkflow: null,
+  canvasWorkflow: createBlankWorkflow(),
   currentCanvasProjectId: null,
   pendingDeleteProject: null,
   deleteProjectSubmitting: false,