Proof-of-Stake Validator Selection & Finality (2D)

This 2D companion models the same proof-of-stake mechanics as the 3D version, but with every validator's stake exposed as its own slider: a ring of validator nodes competes epoch by epoch through a stake-weighted lottery to propose the next block, other validators attest with weight equal to their own stake, and a block finalizes once cumulative attesting stake crosses the 2/3 supermajority. Tick "withhold" on any validator to make it adversarial — it keeps its voting power but refuses to attest — and watch time-to-finality stretch as withheld stake climbs toward the 1/3 safety margin, or watch the chain stall entirely once it's crossed.