cell_significance: per-cell best-combo gain verdicts (provisional)

cell_significance/cell_best_gain.json

@@ -1,6 +1,6 @@
 {
   "schema_version": "cell-best-gain-v1",
-  "generated_at": "2026-09-10T23:09:06.703408+00:00",
+  "generated_at": "2026-09-11T00:12:03.486301+00:00",
   "methodology_doc": "docs/cell-performance.md",
   "axis": "accuracy",
   "alpha": 0.05,