Customize `brightSelect`'s render function so the focused option's
label paints in brand cyan during selection and the submitted answer
paints in dim cyan after the user moves on. Inactive options keep
their default rendering — only the cursor and submitted state pick
up the color, matching the body-text emphasis added in #2101.
Also migrate the one remaining `p.select` call site (the "What next?"
prompt after the first chat) to `brightSelect` so every menu in the
setup flow goes through the same render path. The shape of the call
matches what `brightSelect` already supports — message + options
with value/label/hint — so no feature is lost in the swap.
Reuses `brandBody` from #2101 for the cyan, so the prompt highlight
and the body prose share one definition of the brand body color.
4c791a41b2