MAV-MCC K4-K7 Coherence Fork — Prospective Boundary-Ratio Freeze v0.2-R1

This preprint freezes the next prospective MAV-MCC K4-K7 coherence-fork test after preservation of the Test 01 raw-loss FAIL_TARGET and the separate K8 LOW-polarity diagnostic PASS. The pre-existing bounds are kept unchanged: K6 = 0.500094, K4 = 0.595560, K5 = 0.878984, and K7 = 0.945198, with [K4,K5] defining the CORE interval inside the extended [K6,K7] interval. For future independent tests, the primary coordinate is frozen as the physically native boundary ratio ρ_bound = u_opt/u_bound, where u_opt is the prospectively defined optimal operating point and u_bound is the corresponding instability or bound-state threshold. PRIMARY_PASS requires the target to fall inside the extended fork while a matched control falls outside; STRONG_PASS additionally requires the target to fall inside CORE. K8 = 0.25 is retained as a secondary LOW-polarity diagnostic and cannot override a K4-K7 FAIL. The previous Test 01 result is preserved without post-hoc retuning. The document explicitly separates calibration from prospective validation and freezes the no-retuning, source-provenance, target/control, and failure-preservation rules before analysis of the next eligible dataset.