Realtime deploy notifications in the inbox

Added

• Deploy-aware inbox: public.app_releases upserts the current version on every /api/version call, and every authenticated client subscribes to postgres_changes via Supabase Realtime. Operators see a "new version available" toast with Refresh now / Later within seconds of a release.
• If Later is chosen, a persistent banner re-prompts 30 minutes after dismissal.
• An independent idle-fallback auto-reloads the tab after 10 minutes of no mouse/keyboard activity so pinned-but-untouched tabs don't run an outdated bundle indefinitely. The reload remains deferred while the user is focused in an editable element.

Changed

• The 5-minute polling loop becomes a 10-minute fallback now that realtime is the primary signal.