- serial-linux-selfhosted checks out fetch-depth 0: depth 2 misses
github.event.before on multi-commit or force pushes, failing the
archive verifier on a valid tree. Full fetch is cheap against the
VM's local mirror.
- Runbook (both languages): every remaining admin phrasing (problem
statement, switch heading, alternatives, consequences) now says
writer; and the 'composes with this mechanism' claim about a
master-ref-pinned runner group is replaced with the truth observed
live on 2026-07-27 — master-ref pinning blocks PR failover, and the
shipped posture is repository-scoped all-workflow group access.
Static gate green locally: 32 passed, 0 failed.