Adds Forgejo as a second push target on the build-ci-image pipeline
and saves the just-pushed image as a gzipped tarball on the registry
VM disk (/opt/registry/data/private/_breakglass/) so we can recover
infra-ci with `ctr images import` if both registries are down.
* Dual-push: registry.viktorbarzin.me:5050/infra-ci AND
forgejo.viktorbarzin.me/viktor/infra-ci, in the same
woodpeckerci/plugin-docker-buildx step. Same image bytes; the
Forgejo integrity probe (every 15min) catches any divergence.
* Break-glass step: SSHes to 10.0.20.10, docker pulls + saves +
gzips, keeps last 5 tarballs (latest symlink). Failure-tolerant
so a transient registry blip doesn't fail the build pipeline.
* Runbook docs/runbooks/forgejo-registry-breakglass.md documents
the recovery flow (when to use, scp+ctr import, node cordon,
underlying-issue fix).
Tarball mirrors to Synology automatically through the existing
daily offsite-sync-backup job — no new sync wiring needed.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
