Save the traffic ring buffer to db/server/traffic_cache.json every
two minutes and on SIGINT/SIGTERM before shutdown; restore buckets on
startup. Add setup-linux-production.sh, expand FCM and passkey README
sections, and refresh the clients list after creating a peer on the
clients page.
- Digital Asset Links endpoint and passkey origin handling for the mobile app
- FCM device token registration and push notification plumbing
- Session cookie configuration for native WebView flows
- Routes, locales, README, and small traffic/status handler updates