Migrate now lives at Overview › Migrate › Restore (standalone MigratePage). Strip
it out of BackupPage: drop the migrate sidebar item/panel/modal from the
fragment, the 'migrate' tab from the allowed set / titleFor / subtitleFor /
iconFor, the renderMigrate() call, and the migrate-host/app/confirm click
handlers; delete the now-orphaned backup-migrate.js. The backup center is now
Dashboard/Backups/Locations/Configuration.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>