Point setup copy at Settings → Team #544

The team directory moved to Settings → Team, with a Refresh button. Some copy still points to the old place:

• docs/setup.md: "Settings → This Mac → Team directory" and "Troubleshooting → Refresh status";
• apps/host/src/client.ts:66: "Add it in Settings → This Mac → Team directory, or with ace key set ACE_SECRET".

The web app's connect placeholder shows mac.tailnet.ts.net:5141, the dev HTTPS port, but stable listens on 5140 (apps/app/src/connect.tsx:33,38).