[thelastbackspace]

traceperf run and known-slow example apps

New

• traceperf run <app.js> --path /x [--path /y]: starts the app with traceperf/auto, detects its port, sends warm-up requests, then concurrent traffic (-c, -d/-n, --method), and prints stats plus explain findings. Without --path, use the app and press Ctrl-C. -- npm start runs any command via NODE_OPTIONS. --html, --output, --json.
• examples/slow-apps/: five apps with one planted cause each (blocking, sequential awaits, N+1, slow dependency, errors). run.test.ts runs each and fails if explain misses the cause.

explain fixes found by the example apps

• N+1 no longer also reported as sequential awaits.
• Sequential awaits in one parent grouped into one finding (JSON lines now carry sub-ms startMs; ms-rounded ISO starts split runs).
• Errors listed first; no more "GET /report in GET /report".
• Warm-up requests keep cold-start work from being reported as blocking.

Testing

• 211 tests (3 skipped) pass; coverage above threshold; lint, types, typedoc, 11/11 package checks.
• Verified from a packed tarball against an ESM app outside the repo.