src/lib/rank.test.ts was the last co-located API test. The API tsconfig excludes
tests/ from the build, so all test files belong there; a test in src/ gets compiled
into dist/ and vitest then runs the stale compiled copy (the source of phantom
'22 todo' and dist sourcemap warnings). Moving it to tests/lib/ matches convention
and leaves zero test files in src/, so the production build no longer emits test
artifacts. Updated rank.test.ts path refs in phase-04 plan docs.
Lucas Berger
690f0b95c0