feat: 优化前端手动备份

Author: xream

backend/package.json

@@ -1,6 +1,6 @@
 {
   "name": "sub-store",
-  "version": "2.36.13",
+  "version": "2.36.14",
   "description": "Advanced Subscription Manager for QX, Loon, Surge, Stash and Shadowrocket.",
   "main": "src/main.js",
   "packageManager": "pnpm@11.0.9",

backend/src/restful/miscs.js

@@ -35,6 +35,7 @@ export default function register($app) {
     $app.route('/api/storage')
         .get((req, res) => {
             res.set('content-type', 'application/json')
+                .set('access-control-expose-headers', 'content-disposition')
                 .set(
                     'content-disposition',
                     `attachment; filename="${encodeURIComponent(