Completes the Forgejo domain migration. ROOT_URL moved to dev.jinemi.com
earlier; the registry half was deliberately deferred. Every image name,
REGISTRY_HOST default, runner label and --add-host pin now names
dev.jinemi.com, so the registry host and the bearer-token realm agree again.
Both names address the same Forgejo, so no image needs re-pushing and a
rollback to a tag pushed under the old prefix still resolves.
git.thermograph.org therefore stays served off the same Caddy site block --
one block, so the /v2/* mesh-only matcher keeps covering both names -- for
pre-migration tags and for runners holding it as their registered instance
URL.
Mesh clients now pin both names in /etc/hosts: the new one as registry host
and token realm, the old one for pre-migration tags. runner-vps2/config.yaml
carries both --add-host entries for the same reason.
Also renames Centralis' endpoint to mcp.jinemi.com in the two places this
repo names it; Centralis itself is provisioned outside this repo.
Host-side steps this cannot do (documented in deploy/forgejo/README.md,
"Host-side steps"): the Forgejo Actions variable REGISTRY_HOST, docker login
against the new host, and the /etc/hosts pins.
