Ambitious continuation of union-closed on https://github.com/wustep/maths from current main. Read AGENTS.md and problems/union-closed/.

Current record: 0.38304 on {b,1} with pure Liu Example 4 (β=1), above 0.38285 and Liu 0.382709. Analytic crossing ~0.383051. Not 1/2. Same class as Liu Theorem 13.

This is NOT a small-dent pass. Hunt a certified frequency strictly above 0.38304, toward 1/2, on a checkable hypothesis class (new β, Example-5 mixes, 3-point support, or a new protocol) with an independent mesh/verifier. Work in compute/q2/. Replay compute/q1/run_all.sh first. Fetch Gilmer and Liu before claiming. Do not claim Frankl 1/2 unless you prove it.