Restore Objective Grounds to Fix Mechanism Design Flaws

Mechanism design fails when a subjective proxy replaces an objective ground. Four cases: consensus, cross-domain state, governance, attention. Repair: restore objectivity structurally. UTXO needs blind pairwise commit-reveal; commingled balances need per-lot bucketing; governance needs an external floor. Attention needs merit-priced discourse layer, replace engagement. Buildable now.