pre-register item 17: GSM-only prompt-only arm (last missing cell of the GSM question)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

results-loop/PROTOCOL_UNIFIED.md

@@ -324,3 +324,15 @@ h2048 single seed) were upper-tail draws of the same distribution the
 merge's 46.4 came from. No recipe amendment; the abstract's original
 "same level within noise" framing stands; single-cell records are not
 levels — only seed means are.
+
+17. **GSM-only, current recipe (pre-registered 2026-07-15 ~20:45, before
+    running).** train_merge_unified.py --tasks gsm: MergeAdapter, prompt-
+    only loop, curriculum, GSM8K data ONLY — removes the mixed-task
+    interference confound from the adapter_uni run, completing the
+    "winning recipe trained on GSM" question. Eval: prompt-only, n=256,
+    ks 0,1,2,4, e400. Predictions: (a) hard <= 10% at every k (supervision
+    density is structural: ~3 answer tokens; the recipe's dense-output
+    ingredient cannot exist here); (b) easy damaged at k>0 (to 40-70%);
+    (c) overall never beats k=0. If hard exceeds 15% or overall beats
+    k=0, task interference in the mixed run was masking a real GSM
+    capability — would reopen the GSM chapter.