## Summary
- serialize the remaining login tests that mutate or read the
process-global auth environment
- include Bedrock auth-manager tests in the existing `codex_auth_env`
serial group
## Root cause
The login unit-test binary runs tests concurrently. One test removed
`CODEX_ACCESS_TOKEN` without joining the existing serial group, while
several Bedrock tests constructed `AuthManager` and read that same
process-global environment outside the group. An interleaving could
restore a stale personal access token while another test was loading
file-backed auth, causing the observed mismatched `/whoami` request
count and related auth-state flakes.
## Verification
- `just fmt`
- `git diff --check`
- `bazel test //codex-rs/login:login-unit-tests --nocache_test_results
--runs_per_test=20 --test_output=errors` (20/20 passed)
- `just test -p codex-login` (135/135 passed)
jif
b65fe3d897