Surfaces live connection health for the active instance in the sidebar
and probes localhost:8000 on the first-run choose-type screen so users
running Honcho locally can connect in one tap.
- useHealthStatus hook polls checkConnection every 30s via TanStack Query
- HealthDot component renders a colored status dot with tooltip
- choose-type screen silently probes http://localhost:8000 once; on
success it surfaces a "Detected Honcho at localhost:8000 — tap to
connect" banner that opens the self-hosted form
