The Cross-Face Orientation Is a Two-Port Endpoint–Wronskian Instrument
Integration by parts decomposes the oriented face difference as
The endpoint amplitude is reciprocal-even. The bulk Wronskian phase current is reciprocal-odd. They are independent and form the minimal faithful two-port orientation instrument.
The remaining theta-specific gate is to identify J(K) with a declared
primitive, square, odd principal-value, or modular seam current. Endpoint
control alone cannot reconstruct it.
Research packet:
research/grothendieck/the-cross-face-orientation-is-a-two-port-endpoint-wronskian-instrument.md
Checker:
research/grothendieck/checkers/check_cross_face_endpoint_wronskian_instrument.py
The checker passes 6/6 gates.