Direct second-order zero-sum game solving

Five claims: exact DRS identities, operator geometry, local quadratic steps, and one-time hybrid switches.

Theorem 1

108 LP-referenced lift/project cells; max residual 1.10e-14.

Lemma 1

4,320 pairs; max Lipschitz ratio 0.953 and 1,353 destructive scaled violations.

Theorem 4

36 local trajectories, 72/72 accepted steps; max residual-squared ratio 1.37.

Hybrid

18 one-time switches finish below 1e-9. The 400x800 timing table remains source-reported.