Twin of #12022 on main: CodeQL flagged the same input-controlled checkout + npm cache pattern (cache-poisoning/poisonable-step) on main since it's the default branch. Checkouts go back to github.ref; dispatch still works via --ref (documented in the workflow's own on: contract).
Also fixes the packaged-app smoke: it now waits on /api/monitoring/health (which touches the DB) instead of /login (which doesn't), so the smoke can actually distinguish "native driver selected" from "database never opened." electron-smoke-script.test.ts 9/9 (2 new cases).