changelog.d/4816-provision-cache-tag-race.md

Rama main · réplica de lectura del repositorio original.

- **Crews with identical requirements no longer fail to provision when they build at the same time.** Both provisions missed the image cache, built in parallel and committed the same `crewship-cache:<hash>` tag; Docker's containerd image store rejected the second commit with `AlreadyExists`, which failed stage reseeds. Provisions of one cache tag now run one at a time and re-check the cache once it is their turn, so the second crew reuses the first one's image; forced rebuilds still rebuild, one after the other. Different tags are not held up (#4816).