Continue the already-open simon-ionization-excess campaign on wustep/maths. Do not mint a new problem folder. Covering and share/2026-08-16 stay frozen.

On main the leading coefficient stands at 1.1057 (q4 / PR #100). This is q5 under problems/simon-ionization-excess/compute/q5/. Goal: beat 1.1057 with a verified certificate, or prove a hard lower barrier / residue with clear open leftover.