Mirrors the activity the app already computes (bell, crews, DMs, newsletter)
to the OS notification shade, with no new relay traffic and no new network
destination.
- src/lib/osNotify.ts: one delivery API. Web uses the Notification API; native
uses @capacitor/local-notifications (lazily imported, so the web bundle never
pays for it). Tap-through navigates in-app.
- src/components/OsNotificationBridge.tsx: mounted once in Layout, inert until
opted in. Per-source silent priming + a seen-id set means history is never
replayed as a flood, and it stays quiet while the app is visible (the bell
already covers that).
- DMs notify from the gift-wrap ENVELOPE only (src/hooks/useDmEnvelopes.ts,
no decryption) — so Amber is never prompted just to be told you have a
message. Preview is honestly generic.
- src/lib/notificationPrefs.ts + useNotificationPrefs: device-local, opt-in,
default off, per-category toggles. Settings -> Notifications UI.
Deliberately local-only: a fully closed app needs a server push, which is not
built (Phase 2 = on-device background runner; Phase 3 = content-free FCM).
