The bar's default radius, in km, read back from the slider that carries it.
Single reader for that default: the label, the toolbar button and the deactivation
path all resolve it here, so they can no longer disagree. Parsed as a float — the
profile is free to declare a fractional radiusDefault, and truncating it silently
moved the painted circle away from the value shown next to it.
Returns number
The slider default when it is a usable radius, else DEFAULT_RADIUS_KM.
The bar's default radius, in km, read back from the slider that carries it.
Single reader for that default: the label, the toolbar button and the deactivation path all resolve it here, so they can no longer disagree. Parsed as a float — the profile is free to declare a fractional
radiusDefault, and truncating it silently moved the painted circle away from the value shown next to it.