V3 Rust Cargo toolchain capability pack. By-value connector composition (service_kind=cli, no separate ingredient): one local cargo CLI ingredient exposes bounded project operations for readiness, compile checking, test execution, and Clippy diagnostics. Project operations run from an explicit project directory cwd supplied at execution time, use locked dependency resolution, avoid caller-supplied Cargo flags, avoid shell wrappers, and keep diagnostics visible as text or JSONL output. Compile, test, and lint operations are approval-gated because Cargo may compile project code, execute build scripts and proc macros, invoke toolchain helpers, run tests, and write target cache state. Requires cargo on PATH; Clippy operation also requires the clippy component.