## What changed
- Co-locate the Bash and zsh snapshot-script tests with
`codex-shell-command`, where `snapshot_script` is implemented.
- Add `tempfile` as a dev dependency for the relocated tests.
- Keep the higher-level snapshot lifecycle tests in `codex-core`.
GitOrigin-RevId: 6d5e9ab95962722f7c89ea40512bd70ee81d8da2