setup-rust-cilisted

# Setup Rust CI CI is a promise the tooling keeps in public. The workflow this skill writes runs on every push and pull request, and the first thing a contributor learns about the repo is the tick or the cross. It runs only when the user invokes it — a workflow executes on someone's behalf, and the model never decides that on its own. The whole run is governed by one rule: **read the recorded posture first, and make CI say exactly what the local tooling says.** ## What this writes, and the one rule One workflow file, `.github/workflows/rust.yml`, plus a line in the contributing notes the repo keeps, if it has them. The rule: **the CI job runs the same commands the skills run locally, at the same level, or CI is lying.** A workflow whose clippy invocation is stricter than the repo `[lints]` block produces failures nobody can reproduce; one that is laxer produces a green tick that means nothing. The full file, and the variants, are in `WORKFLOWS.md`. ## Read the posture first `docs/agents/rust.md` — written by `/setup-rust-skills` — carries edition, MSRV, async runtime, `no_std` posture, and unsafe policy. Every one of those changes the workflow: MSRV decides whether there is a second toolchain job, `no_std` decides whether `--target` matters, and the unsafe policy decides whether a Miri job earns its slot. If the file is absent, say so and offer to run `/setup-rust-skills` first — do not guess a posture and bake the guess into CI. ## The three jobs that always earn their