pub fn toon_columns(gt: &GrainType) -> &'static [&'static str]Expand description
TOON column names per grain type, per CAL spec Section 10.9.3.
Reads from the grain-type metadata registry (D1) — the single source of truth for the byte ↔ string ↔ plural mapping plus the per-type TOON column set — so this is not a third hand-maintained copy of the same data.