scripts/check-phase16.sh runs the layer unit tests, the layer playground
SSR smoke, the site app install/build/tests/smokes, the host boot tests,
the grzyby command tests with -race and check-deploy. Each stage fails on
not ok, fail/skip/todo/cancelled counts, missing named tests, go test
failures, skips, no tests to run, data races or a smoke without ok; it
ends with "Phase 16 gate passed".
