Phosphor radar scope: a rotating sweep beam with a soft angular-gradient afterglow over concentric range rings and faint azimuth spokes; seeded contacts blip awake when the beam crosses them, bloom, then decay — drifters leave breadcrumb tracks. Optional hud knob for the full instrument look. Canvas 2D, seeded, offscreen-paused, DPR-clamped, reduced-motion-safe.
pnpm dlx shadcn@latest add "https://crucibleui.com/r/sonar.json"