OptionalcharSingle character used to draw the top/bottom lines.
Default: "=". If you pass a multi-code-unit string, it will be repeated as-is
without width measurement (see grapheme note in banner).
OptionalcolorForeground color for both the banner lines and the headline text.
Color names/hex are parsed by colorText. Invalid inputs fall back as implemented by that function’s underlying utilities.
OptionalspacingIf true, insert a blank line before and after the banner block.
OptionalstyleText style transform. Applied before coloring.
Options to control the visual appearance of banner.