Captures the escape-hatch procedure used to ship v1.15.12 on 2026-05-28
when buildkit cache-export mode=max started returning HTTP 400 from the
Hub CDN, breaking five consecutive CI publishes (runs #332/333/334/336
+ a rerun).
- docs/manual-host-publish.sh: the literal script that shipped v1.15.12
from a developer Mac via Orbstack, preserved as-is for future reference.
- docs/manual-host-publish.md: runbook explaining when to reach for it,
the four constants to edit, three ways to source BASE_HASH (CI log /
Hub probe / local recompute matching base-decide's exact recipe
including __pycache__/.DS_Store junk filters), and adaptations for
pi-devbox / letter-suffix rebuilds / partial-failure recovery.
- AGENTS.md: new Critical conventions bullet documenting the cache-from
/cache-to disablement, failure shape, repo-specificity, why action
pinning didn't help, the trade-off, and the re-enable condition.
Cross-references CHANGELOG v1.15.12 Unreleased + the new runbook.
pi