A push that only changed Cargo.lock failed to create any Actions run while the
concurrency group was present; removing it restores reliable push triggering.
Single-dev CI doesn't need run-cancellation.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
CI runs on a self-hosted host-mode gitea-runner on the desktop (label `arch`),
so the cheap gitbutter VPS only queues jobs while all compile/test compute runs
locally. Pipeline on push-to-main / PR / manual dispatch: cargo fmt --check,
clippy --all-targets -D warnings, cargo test --all-targets + doc tests, cargo
deny check, cargo audit.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>