Antenna height now drives typical/extended/exceptional range estimates
and viewshed max range via a sqrt(h_m/10) factor clamped to [0.6, 2.0].
Baseline 33 ft matches the existing defaults. Changing the height input
now pushes update_band_info and refreshes the clicked point's detail
panel plus viewshed so the range-estimate line and coverage shape track
the user's actual station height.