## Why
`codex-core` was re-exporting APIs owned by sibling `codex-*` crates,
which made downstream crates depend on `codex-core` as a proxy module
instead of the actual owner crate.
Removing those forwards makes crate boundaries explicit and lets leaf
crates drop unnecessary `codex-core` dependencies. In this PR, this
reduces the dependency on `codex-core` to `codex-login` in the following
files:
```
codex-rs/backend-client/Cargo.toml
codex-rs/mcp-server/tests/common/Cargo.toml
```
## What
- Remove `codex-rs/core/src/lib.rs` re-exports for symbols owned by
`codex-login`, `codex-mcp`, `codex-rollout`, `codex-analytics`,
`codex-protocol`, `codex-shell-command`, `codex-sandboxing`,
`codex-tools`, and `codex-utils-path`.
- Delete the `default_client` forwarding shim in `codex-rs/core`.
- Update in-crate and downstream callsites to import directly from the
owning `codex-*` crate.
- Add direct Cargo dependencies where callsites now target the owner
crate, and remove `codex-core` from `codex-rs/backend-client`.
## Why
PR #13783 moved the `codex.rs` unit tests into `codex_tests.rs`. This
applies the same extraction pattern across the rest of `codex-rs/core`
so the production modules stay focused on runtime code instead of large
inline test blocks.
Keeping the tests in sibling files also makes follow-up edits easier to
review because product changes no longer have to share a file with
hundreds or thousands of lines of test scaffolding.
## What changed
- replaced each inline `mod tests { ... }` in `codex-rs/core/src/**`
with a path-based module declaration
- moved each extracted unit test module into a sibling `*_tests.rs`
file, using `mod_tests.rs` for `mod.rs` modules
- preserved the existing `cfg(...)` guards and module-local structure so
the refactor remains structural rather than behavioral
## Testing
- `cargo test -p codex-core --lib` (`1653 passed; 0 failed; 5 ignored`)
- `just fix -p codex-core`
- `cargo fmt --check`
- `cargo shear`
## Summary
- Reduced repeated approvals for equivalent wrapper commands and fixed
execpolicy matching for heredoc-style shell invocations, with minimal
behavior change and fail-closed defaults.
## Fixes
1. Canonicalized approval matching for wrappers so equivalent commands
map to the same approval intent.
2. Added heredoc-aware prefix extraction for execpolicy so commands like
`python3 <<'PY' ... PY` match rules such as `prefix_rule(["python3"],
...)`.
3. Kept fallback behavior conservative: if parsing is ambiguous,
existing prompt behavior is preserved.
## Edge Cases Covered
- Wrapper path/name differences: `/bin/bash` vs `bash`, `/bin/zsh` vs
`zsh`.
- Shell modes: `-c` and `-lc`.
- Heredoc forms: quoted delimiter (`<<'PY'`) and unquoted delimiter (`<<
PY`).
- Multi-command heredoc scripts are rejected by the fallback
- Non-heredoc redirections (`>`, etc.) are not treated as heredoc prefix
matches.
- Complex scripts still fall back to prior behavior rather than
expanding permissions.
---------
Co-authored-by: Dylan Hurd <dylan.hurd@openai.com>