Fix file sharing load speed and move error; misc updates

- Remove recursive directory size calculations (single Seafile API call per list)
- Remove 'Used in this location' usage display
- Fix move using v2 per-type endpoints instead of broken batch endpoint
- Send entry type from frontend for correct move routing

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

vercel.json

@@ -1,3 +1,3 @@
 {
-  "rewrites": [{ "source": "/(.*)", "destination": "/index.html" }]
+  "rewrites": [{ "source": "/((?!\\.well-known).*)", "destination": "/index.html" }]
 }