//! The deterministic series colour walk ([CHARTS.md] §10). One ordered hue
//! sequence, skipping `red` (reserved for danger), wrapping when exhausted — shared
//! by series colour assignment and (later) pie / bubble per-datum colour, so the
//! walk lives in exactly one place.
/// The hue order, `red` deliberately absent. Interleaved around the hue wheel (every
/// adjacent pair ≥ ~90° apart in OKLCH hue), not marched warm→cool, so neighbouring
/// series read as distinct — the common 2–4-series case gets the strongest contrast.
const WALK: & = &;
/// The palette-var hue name for the `i`-th coloured datum (the bare base tier — a
/// `--name` reference resolved by the renderer, so it themes / flips / bakes).