Operator picks a version from a Gitea-populated dropdown; the hub reads that
version's sha256 from Gitea itself (files-metadata API, no artifact download) and
vouches it — no hand-copied checksums. New internal/gitea read-only client
(ListVersions + FileSHA256, unit-tested). Configuration UI: version <select>s +
read-only sha display; handleSetArtifacts derives the sha authoritatively and
refuses the save on a Gitea lookup failure. Degrades to manual text entry without
registry creds. go build/vet/test clean.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
