EnableNotifications subscribes the owner's device with the public VAPID
key and stores it; sw.js receives pushes and opens /defects on click;
`pnpm vapid:keys` mints the key pair.
Drizzle schema for projects, defects, push_subscriptions (C8); generated
migration; a defects repository (createDefect / listRecentDefects); a
programmatic migrator; and a db:verify script. section_id is a plain string
referencing in-code board ids, no FK (ADR 0001). Verified against real
Postgres: migration applies, a defect round-trips, /api/health reports db up.