Manuscript revision and pending experiment work, snapshot before restructuring

Clarity pass over the main text (36-item audit), Discussion rewrite and cut,
acknowledgements, Souly et al. as ref 62, lettered SI panels, model section
moved under Results; plus the untracked curriculum/society/compose/smol
configs, runners, figures, stats and tests that the SI already cites.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y64o8FKP7rCuXzC48pxpMm

configs/llm/compose_gate.yaml

@@ -0,0 +1,31 @@
+# Generation-0 gate for the composition experiment (prereg v3 §4: C1 base, C3 specialists,
+# C4 replication). Trains the two founders and measures everything at t=0 without iterating.
+#
+# Base choice (C1, measured 2026-09-07): Qwen2.5-1.5B **base, not Instruct**. Zero-shot GSM-Hard
+# program-aided: Instruct-1.5B 0.500, Instruct-3B 0.417, base-3B 0.633 — all far too strong, since a
+# base that already has the skills makes the specialists' contribution vacuous. Base-1.5B scores
+# 0.067, within noise of the 0.059 Llama-2-7B starting point in LoRA Soups (COLING 2025), so the
+# published composition effect has room to appear.
+experiment: llm_compose_gate
+kind: llm_compose
+base_model: Qwen/Qwen2.5-1.5B
+seed: 1
+generations: 0            # gate only: train founders, measure t=0, stop
+arms: [dry]
+n_hard: 150               # composed target (GSM8k-Hard, program-aided) — SE ~0.04
+n_gsm8k: 100              # math own-skill probe
+n_mbpp: 80                # code own-skill probe (execution-verified)
+n_probe: 40               # shared prompts for rho
+k_inherit: 300
+epochs: 3
+conf_gate: 0.85
+g: 0.10
+spec_train: 1200
+spec_epochs: 3
+max_new_tokens: 320
+batch_size: 16
+score_batch_size: 4
+train_batch_size: 2       # 16 GB A4000; the fp32 logit upcast at vocab 152k is the constraint
+train_max_len: 448
+lora: {r: 16, alpha: 32}
+output: {dir: results/llm_compose_gate}