fix(web): 修复 .soon/模板加载、旧文件兼容与另存为离开提示

- 删除 design1 ui 遗留代码，修复加载竞态与新建不弹保存提示
- cloud-files 归一化旧版 .soon，IndexedDB 写入完成后再跳转设计页
- 模板/本地 .soon 首次保存须另存为，离开前统一确认
- 发版缓存 bust（version.js、soon-cache.js）及宝塔 Nginx 配置文档

Co-authored-by: Cursor <cursoragent@cursor.com>

docker/nginx/frontend.conf

@@ -9,8 +9,18 @@ server {
     location = / { return 302 /pages/index.web.html; }
     location = /pages { return 302 /pages/index.web.html; }
     location = /pages/ { return 302 /pages/index.web.html; }
+    location ~* \.(html|web\.html)$ {
+        add_header Cache-Control "no-store, no-cache, must-revalidate, max-age=0" always;
+        add_header Pragma "no-cache" always;
+        add_header Expires "0" always;
+        try_files $uri =404;
+    }
+    location = /config/version.js {
+        add_header Cache-Control "no-store, no-cache, must-revalidate, max-age=0" always;
+        try_files $uri =404;
+    }
     location ~* \.(js|css)$ {
-        add_header Cache-Control "no-store, no-cache, must-revalidate";
+        add_header Cache-Control "no-store, no-cache, must-revalidate, max-age=0" always;
         try_files $uri =404;
     }
     location / { try_files $uri $uri/ =404; }