Give the Runner a way to read each component's CURRENT version so it can be
compared against the release sources already wired. Three pure extractors turn
raw system text into an updates.Version, each fail-closed:
- versionFromCLI — a `<tool> --version` banner (k3s, cloudflared)
- versionFromImageRef — a container image tag (felis-api)
- versionFromJarName — a proxy jar filename (velocity)
sysGatherer routes each Topology component to the right extractor over an
injected seam; every path is exercised with a fake runner, mirroring how the
release sources are proven against httptest.
The load-bearing case is k3s: its Git tag "v1.36.2+k3s1" parses stable, but a
registry cannot store '+', so the same build ships as image tag "v1.36.2-k3s1",
which parses as a prerelease unless repaired. versionFromImageRef normalizes
"-k3sN"/"-rke2rN" back to "+", so an image read and a CLI read agree instead of
the image masquerading as a prerelease and being barred from comparison.
Honest runtime state after this slice — a green suite is not "the updater runs
against real infra": only the CLI seam (execRunner) is wired, so of the four
tracked components just cloudflared is live end to end (gatherable AND
Scheduled/appliable). k3s is CLI-gatherable but Notify-only. felis-api and
velocity are NOT yet runtime-gatherable: their producing seams — a k8s read of
the control-plane Deployment image, and an off-cluster jar inspection — are left
nil, so both surface an explicit "gather seam not wired" error rather than a
wrong version. felis-api self-update is therefore not functional yet.
Remaining integration (tracked in doc.go): the two producing seams, the concrete
Notifier (SMTP + in-game), the Applier (image bump, cloudflared swap), the
`felis update` CLI + CronJob entry point, and the runtime append of the Pinned
Minecraft fleet.
