Migrate to Euro-Office and refresh the editor home experience.

Swap Document Server to Euro-Office, add blank-document creation, and restyle the app with an Office-like light/dark theme and compact editor toolbar.

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

packages/backend/src/utils/formats.ts

@@ -78,6 +78,8 @@ export function mimeFor(ext: string): string {
     rtf: 'application/rtf',
     txt: 'text/plain',
     csv: 'text/csv',
+    hwp: 'application/x-hwp',
+    hwpx: 'application/hwp+zip',
   };
   return map[ext] ?? 'application/octet-stream';
 }