rust-quality-gates

@caliluke

Set up Rust quality gates (cargo check/build, clippy, rustfmt, dead code, unused deps via cargo-machete, doc build, tests) in any Rust repo, wired through `prek` (pre-commit reimagined) with a `check.sh` orchestrator underneath. Use when the user says "add quality gates for Rust", "set up Rust linting", "add clippy", "add cargo clippy and rustfmt", "add cargo checks", "Rust quality gate setup", "add prek for Rust", "add cargo-machete", "Rust pre-commit hooks", or wants to establish code quality infrastructure in a Rust project (as opposed to Go, TypeScript, or Python). Step 12 covers optional cargo-audit/cargo-deny, coverage via cargo-llvm-cov, MSRV verification, miri, and feature-matrix testing via cargo-hack for larger repos.