Paper T15B: Strain-Budget Instrumentation for Photon-Like Corridors in HLE v1 RSBU, Tail Loading, and Corridor-Internal Diagnostics

The original T15B proposed wrapped-phase strain-budget diagnostics on the former HLE v1
six-neighbor gate. The current T15A instead evolves two signed surface channels and reciprocal
contact fields on an occupied FCC graph. We preserve T15B’s diagnostic question and translate
its proposed RSBU, tail, phase-accumulation and axis-participation measurements to gauge-
invariant contact quantities. A declared angular reference scales the measurements but does not
gate the dynamics. One deterministic four-contact path on the 917-site occupied preparation is
sampled for two source-phase preparations. At time two, the plus-channel median utilization
is 0.320387 or 0.252094, while the respective maxima are 1.899870 and 1.647894: typical and
tail behavior separate even on this short path. These are finite-model diagnostic calculations,
not a photon trajectory, a measured coherence limit, a detector event or a complete material
handoff. The self-contained program and Windows runner reproduce the results from the declared
equations without external data.