Companion to PR #358 which moved the staging compose ports off 3100/3101
(Loki conflict on the vSwitch). The Caddyfile staging blocks have the
upstream ports baked in so they need bumping too — already applied
manually on the flagship to unblock staging; this lands it in-repo so it
survives the next cd-infra deploy.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>