Hand-designed challenge worlds for the next phase: isolators each stress one coordination skill (thread a corridor, funnel a bottleneck, split at a fork, work cul-de-sacs, trade coverage for connectivity), and bosses compose them. Every map is drawn programmatically and flood-fill-validated — the numbers below are measured, not asserted. Checkpoints (gold) mark the "prize" regions at each chokepoint. Audit these here; when they look right we wire the loader + the checkpoint reward and train on them.