Move sanitizer into codex-secrets (#12306)
## Summary
- move the sanitizer implementation into `codex-secrets`
(`secrets/src/sanitizer.rs`) and re-export `redact_secrets`
- switch `codex-core` to depend on/import `codex-secrets` for sanitizer
usage
- remove the old `utils/sanitizer` crate wiring and refresh lockfiles
## Testing
- `just fmt`
- `cargo test -p codex-secrets`
- `cargo test -p codex-core --no-run`
- `cargo clippy -p codex-secrets -p codex-core --all-targets
--all-features -- -D warnings`
- `just bazel-lock-update`
- `just bazel-lock-check`
## Notes
- not run: `cargo test --all-features` (full workspace suite)
viyatb-oai