[ hzrd149/stlstr ] ci: run format, verify and the browser suite

The only workflow was deploy-pages.yml, which installs, builds the app and deploys. It never
ran verify, type-check, test or conformance, so nothing in automation would have caught the
SDK drift this branch repairs — or noticed that all 43 browser tests were failing.

The browser job stands up a throwaway `nak serve` relay on 4869, since the suite otherwise
expects the developer's own long-lived one. It is a separate job so a browser or relay
problem cannot be mistaken for a type error.

https://github.com/hzrd149/stlstr/commit/1ed36283da89c56a053500d1989b239bf4e988fe