spec: log execution pass (refresh no-op + bf16 dtype fixes, random-V cancelled, defaults cleanup, T4 split)

Co-Authored-By: Claudypoo <288921227+claudypoo@users.noreply.github.com>

docs/spec/20260531_routing_v2_distinct_basis.md

@@ -265,6 +265,21 @@ eps-guarded division. Arm B remains the cleaner bet.
 
 ## Log
 
+- 2026-05-31 (later): execution pass. (1) Random-V control (#157) CANCELLED: it is
+  structurally rf0-only -- refresh re-extracts the real v_hack and would overwrite the
+  random direction, so it only controls the abandoned frozen regime. (2) Frozen-real
+  route (job 32, rf0) drops deploy hack only ~8pp (0.375->0.297) vs run-31 rf5's ~0;
+  cin_t decays 0.32->0.13 to meet cin_s by step ~7 (staleness). Refresh is the
+  load-bearing knob (journal entry j). (3) BUG: route2 refresh was a silent no-op --
+  `vhack_refresh_every` gated on `v_hack`, which route2 sets None; v_act/v_grad stayed
+  frozen. Fixed (2556919): route2 branch re-extracts v_act/v_grad every N with the
+  quarantine ablated. (4) BUG: route2 quar/v_act crashed on the bf16 real model
+  (A_q/B_q/v_act fp32 vs bf16 x); smoke is fp32 (CPU) so the path never fired. Fixed
+  (80f6b52) with `.to(x.dtype)`, bf16 fwd+bwd validated. (5) vanilla (job30) + erase
+  (job29) already DONE on the substrate -- overlay arms exist; erase~=vanilla (0.274
+  vs 0.276). (6) substrate pool + prog_wide pairs now FastConfig defaults (1086c98);
+  real run needs only --intervention. T4 split: per-mode deploy JSON artifact (#164,
+  unblocked groundwork) vs leakage metric (#161, blocked on route2 deploy numbers).
 - 2026-05-31: spec created from brainstorm. Run 31 (additive route) gave
   deploy-hack=0 on all modes incl held-out + solve-jump 0.375->0.562; confounded
   (gpt-5.5 review + journal entry). Random-V (#157) is the gate.