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>

supabase/migrations/20260409124500_add_fourge_files_update_policy.sql

@@ -0,0 +1,4 @@
+create policy "Team updates fourge files storage" on storage.objects
+  for update to authenticated
+  using (bucket_id = 'fourge-files' and get_my_role() = 'team')
+  with check (bucket_id = 'fourge-files' and get_my_role() = 'team');