Pick up Tailscale without restarting Ace Helper #539

Ace Helper reads the Tailscale identity and tailnet once, when it starts (catalog.ts:72-79, gateway.ts:1083). If Tailscale comes on later, or you switch tailnets:

• Settings → Team's Tailscale row reads Connected, from a fresh tailscale status;
• the running host still has no tailnet, so it serves no tailnet listener and finds no peers;
• creating a channel fails with "Start Tailscale first: every channel belongs to a tailnet."

Nothing says that Ace Helper needs a Restart. Docs mention restarting only after switching tailnets.

The host should pick up a tailnet that appears or changes while it's running, or at least say in Settings and in the failure that it needs a restart, with the Restart button beside it.