Anti-Drift Cognitive Control Loop: A Geometric Coherence Gate for Sovereign Reasoning

Operational folio [emp]: a runtime coherence gate scoring agentic reasoning against the chiral band 0.7 ≤ χ ≤ 0.9539. The boundary is stated exactly as arccos(χ_s) and machine-checked in Lean 4; the v2 correction notice documenting the earlier decimal-boundary error (0.3040 vs 0.30469) is included in full. Applied engineering discipline, not a physics claim.

Part of the Geometrically Ordered Dynamics codex. Formal status of all machine-checked results is tracked in LEAN_VERIFICATION_LEDGER.md (16 modules verified, zero sorry; the two remaining named axioms are declared, not hidden).