ci(pr): give the unit-test job Postgres + Redis services

`npm test` boots env.ts and opens Redis (and Postgres) connections;
without the services the job hangs on ECONNREFUSED until the 10-min
timeout cancels it. Mirror build.yml's quality job — the same setup that
runs `npm test` green — with postgres + redis service containers and
the matching dummy env. Reproduced locally against an empty DB + Redis
with the CI env: 573 tests pass.