## Why
Codex-created linked worktrees do not include ignored files from the
main worktree. Bazel users who keep local overrides in `user.bazelrc`
therefore lose those settings in every new worktree.
The setup must also work on Windows and must not overwrite a file that
already exists in the worktree.
## What changed
The checked-in Codex environment now invokes
`.codex/environments/setup.py`. The script resolves the main worktree
and current worktree, then uses
`copy_from_main_worktree_to_worktree(repo_relative_path)` to copy
ignored files into new worktrees without overwriting existing
destinations.
`main()` currently copies `user.bazelrc`. Additional repository-relative
paths can be added as further calls to the same helper.
## Validation
- Ran the setup script in a linked worktree and confirmed it handles a
missing main-worktree `user.bazelrc`.
- Verified the helper copies a main-worktree file, preserves an existing
worktree file, and creates parent directories for a nested path.
## Summary
- Bump the workspace Rust toolchain from `1.93.0` to `1.95.0` across
Cargo, Bazel, CI, release workflows, devcontainers, and the Codex
environment config.
- Refresh `MODULE.bazel.lock` so the Bazel Rust toolchain artifacts
match the new version.
- Leave purpose-specific toolchains unchanged, including the
`argument-comment-lint` nightly and the upstream `rusty_v8` `1.91.0`
build pin.
- Includes fixes for new lints from `just fix` and a few codex-authored
fixes for lints without a suggestion.
## Why
This adds a checked-in Codex environment configuration so the repo
exposes a ready-to-run Codex action from the app environment metadata.
## What changed
- Added `.codex/environments/environment.toml` with a generated `Run`
action.
- The action runs the `codex` binary from `codex-rs/Cargo.toml` with
`mcp_oauth_credentials_store=file`.
## Verification
- Not run; configuration-only change.