Bidirectional Kernel Closure of the Root-6217 Shape Space: the First Arrival-Time Information Field from the Analytic Critical Ray and the A_ref Certificate Boundary

In the five-dimensional parameter space (x₃, y₃, ρ₅, x₅, y₅) of root 6217, two seed sets each grow an arrival-time field: outward from the analytic critical ray of Paper 09B, inward from the five boxes already pruned by A_ref certificates. For each of the 195 still-active responsibility boxes the paper records the two arrival times T₊ and T₋, the meeting radius T∩, a balance β and an information entropy H_B, and separates "contact" from "effective overlap": it reports no positive-measure overlap between an active box and a pruned box, but 35 boundary contacts, and marks root 131 as the first zero-radius contact nexus (T₊ = T₋ = 0), touching both the critical ray and pruned box 155.