GitHub may mark superseded jobs as `cancelled` when a newer push lands on the same PR or `main` ref. Treat that as CI noise unless the newest run for the same ref is also failing. Matrix jobs use `fail-fast: false`, and `build-artifacts` reports embedded channel, core-support-boundary, and gateway-watch failures directly instead of queuing tiny verifier jobs. The automatic CI concurrency key is versioned (`CI-v7-*`) so a GitHub-side zombie in an old queue group cannot indefinitely block newer main runs. Manual full-suite runs use `CI-manual-v1-*` and do not cancel in-progress runs.

The `ci-timings-summary` job uploads a compact `ci-timings-summary` artifact for each non-draft CI run. It records wall time, queue time, slowest jobs, and failed jobs for the current run, so CI health checks do not need to scrape the full Actions payload repeatedly. The `build-artifacts` job also runs the blocking startup-memory smoke and uploads a `startup-memory` artifact with per-command RSS values for `--help`, `status --json`, and `gateway status`.

Use `pnpm ci:timings`, `pnpm ci:timings:recent`, or `node scripts/ci-run-timings.mjs <run-id>` to summarize wall time, queue time, slowest jobs, and failures from GitHub Actions. For build timing, check the `build-artifacts` job's `Build dist` step: `pnpm build:ci-artifacts` prints `[build-all] phase timings:` and includes `ui:build`. The job also uploads the `startup-memory` artifact.

## Real behavior proof