RESULT 45: no-floor判决=走廊真闭合(β 3e-3→1.1e-5无搁板,天花板塌260×),fail-soft兑现(gn≤0.4零spike权重未中毒 vs 硬底版慢烧); plain全程判死→centered; 2x2关键格c190在飞(cent估计器救plain s190000状态?)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014FAPDWQ49M5Ye3NpTndTpn

1 files changed, 19 insertions, 0 deletions

diff --git a/docs/campaign/CASCADE_ABLATION_PLAN.md b/docs/campaign/CASCADE_ABLATION_PLAN.md
index 9de77a0..2919da6 100644
--- a/docs/campaign/CASCADE_ABLATION_PLAN.md
+++ b/docs/campaign/CASCADE_ABLATION_PLAN.md
@@ -568,6 +568,25 @@ direction), not training-under-fault; wave-2 = co-training with faults injected
 
 
 
+### RESULT 45 (2026-07-18): NO-FLOOR VERDICT — the corridor TRULY CLOSES for the plain lineage (ceiling falls 260x with no shelf); fail-soft property of pure tracking CONFIRMED. Plain judged DEAD as a full-schedule 72M recipe; centered-rescue 2x2 cell in flight.
+fw72m_plain_nf (resume plain s190000, cap_floor 0, exact mirror): COMPLETED 234k, best 3.3838 —
+set at ~195k (matches crown-3's pre-death 3.3836) and NEVER improved after: the cap crushed
+beta 3e-3 -> 9.3e-4@200k -> 2e-4@208k -> 1e-4@220k -> 1.1e-5@232k, monotone with NO SHELF.
+The ceiling is really gone (not a hard-bottom artifact); with res>0.02 persisting at beta=1e-5
+the meter is reading FREE-PHASE contraction loss (state property, beta-independent) — consistent
+with the 07-14 wall-2 regression at 72M/FW ~195k.
+FAIL-SOFT CONFIRMED: gn <=0.4 / drift 0.012 / zero skips / no spike / weights un-poisoned
+(val drifts 3.5 -> 4.1 by SNR-dead noise-walk) — vs crown-3's hard-bottom fail-BURN (gn 29.5,
+cos -0.76, drift 0.39, spike). cap_floor 0 is the strictly safer governor policy; the hard
+bottom bought crown-3 its extra 0.011 of best (floor-fight learning 196-204k) at the price of
+late-run poisoning.
+DECISION (user pre-committed): plain cannot hold the 72M/FW full schedule -> centered. Cheapest
+form = the decisive 2x2 cell fw72m_plain_c190 IN FLIGHT (centered est on the SAME plain s190000,
+cap_floor 0, otherwise identical): centered holds the ceiling -> HYBRID recipe (plain bulk +
+centered tail, ~1.13x cost) is live and 2x2 completes as state-rescuable-by-estimator;
+centered also collapses -> plain bulk bakes the disease in before 190k -> full-run centered only
+(crown stays fw72m_cent 3.3318 at 1.67x).
+
 ### RESULT 44 (2026-07-18): GAP-SOURCE LOCALIZATION — the residual EP gap lives in the TOP-half blocks, split ~evenly attn/ffn; bottom-half EP grads are loss-equivalent to BP.
 bpmix 5-arm, all from cent s200000 through the 215k endgame frame (shared frame; internal A/B
 only, absolutes not comparable to crown lineage). BP reference (allbp) 3.4020; all-EP 3.4245