## Summary
- reduce public module visibility across Rust crates, preferring private
or crate-private modules with explicit crate-root public exports
- update external call sites and tests to use the intended public crate
APIs instead of reaching through module trees
- add the module visibility guideline to AGENTS.md
## Validation
- `cargo check --workspace --all-targets --message-format=short` passed
before the final fix/format pass
- `just fix` completed successfully
- `just fmt` completed successfully
- `git diff --check` passed
## 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`.
When running under WSL, the update command could receive Windows-style
absolute paths (e.g., `C:\...`) and pass them to Linux processes
unchanged, which fails because WSL expects those paths in
`/mnt/<drive>/...` form.
This patch adds a tiny helper in the CLI (`cli/src/wsl_paths.rs`) that:
- Detects WSL (`WSL_DISTRO_NAME` or `"microsoft"` in `/proc/version`)
- Converts `X:\...` → `/mnt/x/...`
`run_update_action` now normalizes the package-manager command and
arguments under WSL before spawning.
Non-WSL platforms are unaffected.
Includes small unit tests for the converter.
**Fixes:** #6086, #6084
Co-authored-by: Eric Traut <etraut@openai.com>
