Updater: progress modal + auto-refresh after restart

Done on 30 August 2026. The dialog holds from the confirmation to "version X is running": downloading, verifying the checksum, restarting. The page then comes back on its own. No percentage bar — the update is one server-side call, so there are no honest percentages, and inventing them would be worse than showing none.

Added

2 July 2026

Finished

29 August 2026