StartTunnel restores readable action menus, clarifies local CLI authentication, and closes revoked sign-in streams promptly.

## Highlights

- Action menus near the right edge of the screen size to fit their items.
- On the StartTunnel host itself, `start-tunnel auth login` and `auth logout` explain that no login is needed there.
- Revoking a sign-in immediately closes its idle streams.
- The unsupported `auth get-pubkey` command is removed.