test(gen-seat): PPL on orcarouter — mean 7.07 / median 5.76, within noise of heresy

Measured against a spec-decode-free probe on GPU1 (fable downed to free the VRAM,
probe torn down after). eval_quality.py aborts PPL under --speculative-config, so
a nospec probe is the only way to read it.

  orcarouter  mean 7.0655  median 5.758
  heresy      mean 6.910   median 5.625   (+2.2% mean)
  our recipe's usual mixed-quant PPL: 7.059 -- orcarouter is identical to it

So orcarouter matches heresy on fidelity and wins on every other axis: MTP
acceptance 58.4% vs 47.2%, zero think-leak, vision 7/8. The gen-seat search that
ran through Cold-Fusion, heresy, and preetpatel is settled on orcarouter.

persistent-memory.md

@@ -122,7 +122,7 @@ _As of 2026-08-21 00:35 — **the Heretic-300 session, and its reversal** (see t
 
 - **🟢 HOMEPAGE — cleaned + themed (Australis Skyfall).** Three real defects fixed (UltraSeedbox on all tabs, Uptime Kuma double-rendered, fiction column counts), AI tab reordered by clickability, then themed from the operator's Skyfall handoff bundle with a background generated by **Arbo** (`t2i-ui-background`, job `13f0891f4e42`). ⚠ **After any recreate the tab bar/wallpaper/i18n vanish for up to ~an hour and then return on their own — do not chase it.** ⚠ CSS is served per-request: a theme change needs a **reload**, not a recreate, and candidate CSS can be injected live via Playwright for seconds-long iteration. → `persistent-memory.d/2026-08-19-homepage-skyfall-theme.md`
 
-- **🟢 GEN SEAT — LIVE = ORCAROUTER (cut over 2026-08-21 01:35, operator directive: seat first so he can test while gates run).** `GEN_MODEL=/tank/aimodels/qwen38-27b-orcarouter-nvfp4-mixed`; healthy in ~4 min; **KV 401,550 tok / 1.53×**; MTP drafter detected and wired (embedding + lm_head shared); **7/7 aliases 200**; **vision correct**; **`<think>` not in the top-20 first tokens** — the Cold-Fusion failure mode is absent on the live seat. Live decode observed at **102-133 tok/s** under load. **ROLLBACK:** `.env.bak-heresy-restored-20260821` → heresy (one line). **✅ ALL GATES PASS** (run against the live seat while the operator tested in parallel): **`<think>` leak 0/30, 0 empty** (h300 scored 8/30 on this instrument); **MTP acceptance 58.4% median @ 117.11 tok/s**; **surface 6/6** (chat, vision, tool-calling, thinking split, 36k-token long-context retrieval, streaming); **abliteration survival 4/4** with no `<think>` leak in any sample (h300's equivalent eval had 2 of 4 open with `<think>Ok, let's figure this out:`); deterministic quality gens coherent. **★ THE IN-BAND MTP HEAD PAID OFF: 58.4% vs heresy's byte-identical base head at 47.2% — +11 points**, and level with our own in-band L35 at 59.1%. That is the additive delta the entire Cold-Fusion experiment was built to measure and never cleanly delivered; orcarouter handed it over for free. ⏳ PPL still blocked on a spec-decode-free probe seat (needs ~22 GB, GPU1 has ~16 GB free) — comparison target heresy 6.910. Replacement for the abandoned Cold-Fusion line. Source `orcarouter/Qwen3.8-27B-Uncensored` (rev `9878936b…`, 55.5 GB, gated but our token has access) → `/tank/aimodels/qwen38-27b-orcarouter-nvfp4-mixed` (23.4 GB). Chosen over `preetpatel/…-NVFP4` — full evaluation in `docs/pfi/gen-seat-candidate-eval-2026-08-21.md`.
+- **🟢 GEN SEAT — LIVE = ORCAROUTER (cut over 2026-08-21 01:35, operator directive: seat first so he can test while gates run).** `GEN_MODEL=/tank/aimodels/qwen38-27b-orcarouter-nvfp4-mixed`; healthy in ~4 min; **KV 401,550 tok / 1.53×**; MTP drafter detected and wired (embedding + lm_head shared); **7/7 aliases 200**; **vision correct**; **`<think>` not in the top-20 first tokens** — the Cold-Fusion failure mode is absent on the live seat. Live decode observed at **102-133 tok/s** under load. **ROLLBACK:** `.env.bak-heresy-restored-20260821` → heresy (one line). **✅ ALL GATES PASS** (run against the live seat while the operator tested in parallel): **`<think>` leak 0/30, 0 empty** (h300 scored 8/30 on this instrument); **MTP acceptance 58.4% median @ 117.11 tok/s**; **surface 6/6** (chat, vision, tool-calling, thinking split, 36k-token long-context retrieval, streaming); **abliteration survival 4/4** with no `<think>` leak in any sample (h300's equivalent eval had 2 of 4 open with `<think>Ok, let's figure this out:`); deterministic quality gens coherent. **★ THE IN-BAND MTP HEAD PAID OFF: 58.4% vs heresy's byte-identical base head at 47.2% — +11 points**, and level with our own in-band L35 at 59.1%. That is the additive delta the entire Cold-Fusion experiment was built to measure and never cleanly delivered; orcarouter handed it over for free. **✅ PPL MEASURED 2026-08-21 (fable downed to free GPU1, nospec probe on GPU1, torn down after): mean 7.07 / median 5.76** vs heresy 6.910 / 5.625 — **+2.2% mean, within noise**, and identical to our recipe's usual mixed-quant PPL of 7.059. So orcarouter MATCHES heresy on fidelity and beats it on every other axis (MTP 58.4% vs 47.2%, no think-leak 0/30, vision 7/8). ORCAROUTER IS A CLEAN WIN — the gen-seat search is settled. Replacement for the abandoned Cold-Fusion line. Source `orcarouter/Qwen3.8-27B-Uncensored` (rev `9878936b…`, 55.5 GB, gated but our token has access) → `/tank/aimodels/qwen38-27b-orcarouter-nvfp4-mixed` (23.4 GB). Chosen over `preetpatel/…-NVFP4` — full evaluation in `docs/pfi/gen-seat-candidate-eval-2026-08-21.md`.
   - **★★ THE MTP HEAD IS ALREADY ROBINSON-ABLITERATED IN-BAND BY THE AUTHOR — the first third-party build we have seen get this right.** Operator asked whether we could apply the Robinson path to the head; the answer is that it is already applied. `compare_mtp_head.py` vs the verbatim base graft: **13 of 15 tensors byte-identical, exactly 2 differ** — `mtp.layers.0.{self_attn.o_proj,mlp.down_proj}.weight`, which are **precisely the two residual writers our own `abliterate.py` targets** (`EXPECT_MTP_WRITERS = 2`). Reverse-engineered from the weights alone (`bench/think-leak/mtp_delta.py`): **σ₂/σ₁ = 0.0164 on both** (rank-1 → a single-direction projection), **|cos| between the two recovered directions = 1.0000** (ONE shared direction, Robinson's `direction_scope=0` shape), ‖Δ‖/‖W‖ = 1.42%/1.41%, and **sink energy in dim 3994 = 0.0000%** — sink-clean outright, where Heretic's was 6.18% and our L35 0.094%. **Nothing for us to do on the head; only preserve it.** Verified preserved: the quant's MTP head is byte-identical to the bf16 source. This is the configuration the entire Cold-Fusion experiment was designed to test and never cleanly delivered.
   - **★ FORMAT SCREEN PASSED — the new gate paid off immediately.** `think_prior.py` on the bf16 *before* any GPU time: **P(`<think>`) = 1.23e-06, rank 52.** Same probe: Cold-Fusion stock 0.1850, h300 0.2216, heresy <0.002. **~150,000× cleaner than the base we just abandoned.** Base is stock `Qwen/Qwen3.8-27B` + Arditi-et-al. abliteration — not a reasoning-compression finetune.
   - **Artifact verified:** mixed-precision (group_0 FP8 W8A8 / group_1 NVFP4 W4A4), 1968 tensors, **15 mtp**, **333 visual**, `re:^mtp.*` present in the 303-entry ignore list, preproc restored, index built.