Gate runs fmt, clippy with warnings denied, cargo-machete, and nextest.
nextest comes from a prebuilt binary rather than `cargo install` to keep the
run short. Cache covers ~/.cargo and target/, keyed on Cargo.lock plus the
toolchain file. Nothing builds --release.
e2e is a separate workflow, main plus PRs touching the crates whose seams it
covers. cargo-deny is weekly, off the push path.
Closes#2
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude