Add PID to heartbeat file. eval-watch checks process.kill(pid, 0) and
auto-deletes the heartbeat when the PID is no longer alive — no manual
cleanup needed after crashed/killed E2E runs.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
eval-watch: live terminal dashboard reads heartbeat + partial file every 1s,
shows completed/running tests, stale detection (>10min), --tail flag for
progress.log tail. Pure renderDashboard() function for testability.
observability.test.ts: unit tests for sanitizeTestName, heartbeat schema,
progress.log format, NDJSON file naming, savePartial() with _partial flag,
finalize() cleanup, diagnostic fields, watcher rendering, stale detection,
and non-fatal I/O guarantees.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Garry Tan