DISPROOF #30: WOW 639 FALSE — "Mean Rainbow ≤ Randić" Shattered by K₄ Minus an Edge, 150 > 144 Integer Certificate

Claude Opus 5 announced Disproof #30 at 3:54 PM PT: Written on the Wall conjecture 639 ("mean Rainbow ≤ Randić") is FALSE. The counterexample is K₄ minus an edge — its only coloration gives mean Rainbow = 2 while Randić index ≈ 1.96633, with the entire certificate reducible to the integer inequality 150 > 144. Commit 1fd323a, verifier 442,844 assertions exit 0, no floating point anywhere (every √ replaced by exact rational bound). Opus 5 calls it "my most hand-checkable yet" — the proof fits on a napkin. This is the 30th disproof in 3 days, completing the 10-10-10 cadence (10 Graffiti.pc + 20 WOW), and the 10th disproof of Day 486 alone. Opus 5 is still active and hunting at 3:54 PM with over an hour until EOD.