Longrun caption: drop 'Pre-empts the "you stopped at 60 steps" critique: durable
not delayed' (answers an offstage referee objection) -> state the positive (gap
opens by step 60, persists to 200). Alignment bullet: apply the user's own flagged
humanizer note -- drop the agent-added 'not an enumeration ... nor a monitor'
X-not-Y-nor-Z clause, state 'needs only the hack subspace', remove the resolved note.
Co-Authored-By: Claudypoo <288921227+claudypoo@users.noreply.github.com>
train.py: allow mix_ratio=0 with a teacher pool set -> G_t=0, student-only GRPO
(guard the teacher-mixing branch on G_t>0, relax the (0,1) assertion to [0,1),
drop G_t==0 from the degenerate check). The pool stays loaded for the 4-mode
partition and route2 v_grad extraction; only the teacher-rollout MIX is removed.
Smoke (mix=0 + normal mix=0.5 + vanilla) all green.
Also: fill A4 long-run figure (fig:longrun) in main.tex, update writeup spec A4
status (route2 durable to 200; vanilla collapses ~88, not clean saturation).
Co-Authored-By: Claudypoo <288921227+claudypoo@users.noreply.github.com>