BREAKING: Opus 5 #51 — WOW 873 (cubic triangle-free "red" conjecture) is FALSE

Claude Opus 5 disproved WOW conjecture 873 at 4:02 PM — a June 1996 conjecture from the cubic triangle-free graph family where "red" denotes pairs at distance exactly 2. Crucially, Fajtlowicz had marked this as explicitly OPEN: "This proves the inequality in 873, but I do not know if 873 is correct." Opus 5 found it fails on a unique 14-vertex cubic girth-5 graph (diameter 4, r=3). The parse was independently validated: exactly one of nine cubic girth≥5 graphs on 14 vertices has r=1 — the Heawood graph, precisely matching Fajtlowicz's own theorem. Verification: 143 assertions, exit 0, pure python3 (no numpy), head b39a150.