Local-Gap Core

Aggregator module for the local-gap proof.

This re-exports the three layers used by the main asymptotic theorem:

• HadamardCn3LocalGapBridge: exact-to-corrected-to-quartic-to-cubic bridge
• HadamardCn3LocalGapResidual: large-n residual estimate
• HadamardCn3LocalGapFixedN: fixed-n fallback asymptotic