Rasterises enabled tiles into one straight-alpha BGRA frame: measured widths -> FitLine (shrink,
then wrap, never scroll) -> centred lines with dim separators, over an optional rounded plate whose
colour and opacity are the creator's knobs. Uses OutputPalette.Sans (bundled Inter) because on-stream
text wears the app's typefaces.
Static by design: it takes plain strings, so the caller caches the frame and only re-rasterises when
a value changes — a strip that re-rendered every tick would be the compositor's most expensive layer
for no benefit.
Guard: ScoreboardRendererTests paints real frames and inspects pixels — plate colour AND opacity,
text colour reaching glyphs, plate-off leaves the area transparent, and an empty tile set returns no
frame at all.
