Add adaptive and legacy launcher icons for Android.
Replace the default notification icon with a branded monochrome asset.
Add favicon, touch icons, and a web app manifest for the web client.
- register notifications service worker and handle click-to-open chat/message
- route realtime notifications through service worker with fallback
- support ?chat=&message= deep-link navigation in chats page
- enforce 1s minimum voice message length
- lift scroll-to-bottom button to avoid overlap with composer action
