## Summary
- Convert unified exec integration tests that can run against the remote
executor to use the remote-aware test harness.
- Create workspace directories through the executor filesystem for
remote runs.
- Install `python3` and `zsh` in the remote test container so restored
Python/zsh-based test commands work in fresh Ubuntu containers.
## Validation
- `just fmt`
- `cargo test -p codex-core --test all unified_exec_defaults_to_pipe`
- `cargo test -p codex-core --test all unified_exec_can_enable_tty`
- `cargo test -p codex-core --test all unified_exec`
- Remote on `codex-remote`: `source scripts/test-remote-env.sh && cd
codex-rs && cargo test -p codex-core --test all unified_exec`
- `just fix -p codex-core`
`CODEX_TEST_REMOTE_ENV` will make `test_codex` start the executor
"remotely" (inside a docker container) turning any integration test into
remote test.