engine/retro_heroes library

Hand-crafted Retro hardware heroes (docs/m4-design.md §B: ≥ 3 per family), spread into heroThemes (heroes.dart).

Literal ARGB palettes made with the generator's recipe (retro.dart): a plastic body, muted keycaps with one coloured accent, and a 7-segment panel whose lit segments reach 7:1 and whose ghost segments stay near 1.15:1 against it. Ids 50–52 are reserved for this family; never reuse or renumber one.

Constants

retroHeroes → const List<ThemeSpec>

The Retro heroes, ids 50–52.