A 240-degree SVG dial with a spring needle, three-digit readout, unit
label, warning lamp (BRAKE / OVERDRIVE / ENGINE OFF), trip odometer and
gear chip, driven by the journey's own frame loop from the scroll drive,
route progress, navigator state, scene ignition and the high beam. Hover
or focus shows route, exit and time on the road; a click toggles km/h
and mph (remembered). The model and DOM driver load as a lazy chunk so
the initial bundle grows by about 1.3 kB gzipped; reduced motion snaps
the readout, and the bay hides below 1280px.
