A vertical TextField was unavailable, so multiline entry had no Android
equivalent. Store the axis on TextField, carry it across the bridge as
bridgedAxis, and render a vertical field with singleLine off, maxLines
from the lineLimit environment, and minLines when lineLimit reserves
space. Enter inserts a newline in a vertical field, so the hardware-Enter
submit interception now applies only to horizontal fields.

Setting textFieldContentPadding routes rendering through BasicTextField,
which colors its text solely from the text style. styleInfo hands a plain
foregroundStyle color back separately from the style, so only the
OutlinedTextField path — which feeds it through colors: — picked it up,
and a padded field fell back to the default text color unless the
foreground resolved to a brush. Fold the same enabled-aware color into
the text style the BasicTextField renders with.