c5d199eada
The dashboard's update button ran 'hermes update' immediately with no preview. Now the System page shows whether an update is available and asks the user to confirm before applying it. - New GET /api/hermes/update/check: reports install method, current version, and commits-behind (via banner.check_for_updates, 6h-cached; ?force=1 busts the cache). Soft-fails to behind=null on network error; marks docker/nix/homebrew as can_apply=false with the out-of-band cmd. - System page: update-status badge on the Hermes version row (latest / N behind), a Check-for-updates button, and an Update-now button that opens a ConfirmDialog showing the commit count before POST /api/hermes/ update fires. Cached status loads with the rest of the page. - Docs + 5 endpoint tests (git/up-to-date/docker/soft-failure + auth gate).