- .github/workflows/ci.yml: the full `cargo xtask ci` on every pull request and push to main
(Linux x64, craft-fonts, rust-cache for dependencies), so it becomes the merge gate.
- `cargo xtask ci --quick [--base REF]`: fmt, clippy, the changed packages' tests, layers and
assets, plus heif / parity / wasm when the changes touch them, measured against the merge base
with origin/main (xtask/src/ci_quick.rs). Workspace-wide files test everything.
- A machine-wide lock (xtask/src/ci_lock.rs): a second `ci`, from another worktree, waits and
names the run it waits for. LIGHTCRAFT_CI_SLOTS=N, LIGHTCRAFT_CI_LOCK=off|<dir>.
- README, CLAUDE.md quality gate, gaps.md gap 9, target-app-parity.md stability note.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>