CDN-205: The Leak Is Local

CDN-205 audits the CDN-203 source-side failure at delta=0.07. The finite-tail repair is rejected: theta-window floor fits stay near eps_inf = 0.031-0.033, with window span 0.001792, while every fit misses the frozen source prediction by at least 0.019182. A posthoc source/phase-gradient mixture localizes the miss with leakage weight 0.722459, but pure phase-gradient replacement still misses tolerance. The result is a localized hidden-channel clue plus a true frozen-source selector failure.