Adds a self-update path for the NOMAD admin/core image that runs without a
human in the loop, gated by layered safety checks. Recreation remains the
sidecar's job; this only decides *whether* to update now and requests it.
An hourly job (AutoUpdateJob) evaluates a side-effect-free decision pipeline
(AutoUpdateService.evaluate):
- opt-in: disabled by default
- in a user-configured local-time window (handles midnight wrap)
- an eligible release: same major (major bumps stay manual), strictly newer,
past a configurable cool-off, GA only (no drafts/prereleases), strict semver
- pre-flight: sidecar present, no in-flight system update / downloads / app
installs, and sufficient host disk (estimated from the registry manifest)
When all pass, it drives SystemUpdateService.requestUpdate() with a vetted tag.
Failure backoff auto-disables after 3 genuine update-request failures; transient
release-lookup errors are skips (offline-first appliances are routinely without
connectivity). Re-enabling clears the backoff state.
Settings UI exposes the toggle, window, and cool-off, with live status (eligible
target, in/out of window, last result/error). A `node ace auto-update:dry-run`
command exercises the full pipeline — and a deterministic --scenarios suite the
pure decision logic — without ever triggering an update.
New KVStore keys under autoUpdate.* hold config + last-run state.