## Intent
Keep Bazel and Starlark files consistently formatted without requiring
contributors to install or version buildifier themselves.
## Implementation
- Add a SHA-256-pinned, cross-platform DotSlash manifest for buildifier
v8.5.1.
- Run buildifier from the shared `just fmt` and `just fmt-check` driver,
with Windows-safe explicit DotSlash invocation.
- Provision DotSlash in formatting CI and contributor devcontainers, and
document the source-build prerequisite.
- Apply the initial mechanical buildifier formatting baseline.
## Summary
- extract plugin identifiers and load-outcome types into codex-plugin
- update codex-core to consume the new plugin crate
## Testing
- CI
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Co-authored-by: Codex <noreply@openai.com>