Adds Rust to the per-node dev-tool cards: daemon probes rustc → reports 'rust'; nightly checker fetches latest stable from GitHub rust-lang/rust; GET endpoint maps rust→Rust (after docker); one-click update runs 'rustup update stable'. Frontend is data-driven (no change). $HOME/.cargo/bin added to probe candidate dirs. Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>