gamekit — explanations

The game-layer side of the research stack — what lives in handl-lang/gamekit after the plan-0032 phase-4 split.

• The substrate-free kernel — the gamekit ⊥ eqsat contract, the lazy make factories, and the referee seam that keeps the value spec and the measurement on opposite sides.

The full account of boards, players, and the learned-policy loop is a cross-cutting page: the game.