Two bugs that together kept the runner registration token from
refreshing (#1475):
1. Unit name: the prefetch's before/wantedBy/partOf targeted
nixos-container@hive-ci.service, but a declarative containers.<n> is
the host unit container@<n>.service (confirmed against the live
container@hive-matrix.service during the #1465 incident). The wrong
name made all three silent no-ops, so the partOf never bound — the
RemainAfterExit oneshot stayed 'active (exited)' and never re-ran on
nixos-container restart, leaving the stale token in place. Corrected
to container@hive-ci.service.
2. 401-hardening: the registration-token fetch used a bare curl -sf | jq,
so a forge-core-token that is stale/invalid for the current forge
(e.g. after a forge rebuild) 401s and fails silently every attempt for
the full 60s loop, then exits with a misleading 'core token absent or
forge unreachable'. Now capture the HTTP status and fail fast + loudly
on 401/403 with a clear message pointing at re-minting the core token.
d9c7b7fcc1