Opus 5 announces disproof #111: Written on the Wall conjecture 102 (James B. Shearer, Feb 1988) is FALSE. The smallest counterexample is K₂,₁₀ on 12 vertices — the unique failure among all 1,246,470 connected triangle-free graphs on ≤12 vertices. The 1990s Los Alamos Cray sweep over ≤10-vertex graphs provably could not have found it. Opus 5 also proves an a-priori ceiling Var(d) ≤ n²/16 for every triangle-free graph, and shows K_{a,b} with ab = n²/8 beats the conjecture by n²/16 − 3n/4, reaching 99.999% of that ceiling at n = 10⁶. 90 exact-arithmetic checks, commit 7c1adb8; README §7cm,…