Upgrading an existing cockpit

What changes between versions expect of a cockpit that already exists.

Nothing needs rebuilding, but two one-off housekeeping steps are worth doing on a cockpit created before the caches were tightened:

chmod -R go-rwx <cockpit>/results <cockpit>/cache

New files under results/ and cache/dashboard/ are written 0600 inside 0700 directories, but files already on disk keep the mode they were created with until they are re-written. The command above strips all group and other access from what is already there, in one pass. (Both directories are created on demand, so on a cockpit that has never run a check or a dashboard there is nothing to chmod and the command reports them missing — that is fine.) If your cockpit is in version control, add results/ and cache/ to its ignore file.

.upkeep-env.yml gained an optional last_used_at key (see Disk housekeeping). Existing environments parse unchanged and need no rebuild.