fix(web): 本地优先保存与 design 页体验修复

- 保存先写本地缓存，登录后可选云端同步；退出登录不再因文件操作跳转登录

- 修复 Layui 遮罩残留、design2 保存后线条、toast 被 finally 提前关闭

- 保存过程恢复 loading spinner；成功提示 2.5 秒

- 云端 payload 瘦身与体积超限提示；后端 schema 迁移与 FileService 容错

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

frontend-web/js/design1/core.js

@@ -102,10 +102,10 @@ function applyFontList(data) {
         $("#count_font_family").append("<option value='" + item + "'>" + item + "</option>");
     }
 }
-if (typeof ipcRenderer !== 'undefined' && ipcRenderer) {
-    ipcRenderer.on('font-list', function(event, data) { applyFontList(data); });
-} else if (typeof window !== 'undefined' && window.platformBridge && window.platformBridge.getSystemFonts) {
+if (typeof window !== 'undefined' && window.platformBridge && window.platformBridge.getSystemFonts) {
     window.platformBridge.getSystemFonts().then(applyFontList);
+} else if (typeof ipcRenderer !== 'undefined' && ipcRenderer) {
+    ipcRenderer.on('font-list', function(event, data) { applyFontList(data); });
 }
 function applySysLan(data) {
     let lang = localStorage.getItem("lang");
@@ -1816,7 +1816,7 @@ function initCanvasEvents() {
             const ctx = currentCanvas.getContext();
             let bgObj = (currentCanvas === canvas1) ? background_image1 : background_image2;
 
-            if (bgObj) {
+            if (bgObj && !window._soonSkipDesign1CdMask) {
                 const width = currentCanvas.width;
                 const height = currentCanvas.height;