The UI unit test job narrows a pull request to `vitest related <changed
files>`. `related` maps a file to the tests that import it, so a file no
test imports maps to nothing, and `--passWithNoTests` turns that empty
selection into a green job. package.json, package-lock.json, the Vitest,
Tailwind and TypeScript configs and tests/setupTests.ts are all in that
category even though each of them can change the behaviour of every test
in the suite, so a dashboard dependency bump merged having run no unit
tests at all and only got real coverage later, from the full run on the
push to litellm_internal_staging.
Keep `related` for the common case where a pull request only touches
files under src/, and fall back to the full suite as soon as one changed
file sits outside it. The decision lives in
.github/scripts/select_ui_test_scope.sh so it can be tested on its own,
next to the existing classify_changes.sh gate.
