feat(app): open Ace on phones over the tailnet and deploy the web app

Hosts serve the app on their tailnet address to the owner's own devices, with Tailscale naming
the person. A deployed copy on Cloudflare connects to a chosen host over HTTPS when the tailnet
has certificates. The phone layout follows the shared layout's bottom navigation, with the
channel list as a drawer, safe areas, keyboard-aware height and Return adding a line.