feat(gen-seat): quant orcarouter — its MTP head is already Robinson-abliterated in-band

Pulled orcarouter/Qwen3.8-27B-Uncensored at rev 9878936b (55.5 GB, gated, our
token has access) and built /tank/aimodels/qwen38-27b-orcarouter-nvfp4-mixed
(23.4 GB, mixed NVFP4+FP8). Verified, not yet cut over.

The operator asked whether we could apply the Robinson path to the MTP head. We
cannot, because the author already did. compare_mtp_head.py against the verbatim
base graft: 13 of 15 tensors byte-identical, exactly 2 differ --
mtp.layers.0.self_attn.o_proj.weight and mtp.layers.0.mlp.down_proj.weight, which
are precisely the two residual writers our own abliterate.py targets
(EXPECT_MTP_WRITERS = 2).

Reverse-engineered the edit from the weights alone (mtp_delta.py, added here):

  sigma2/sigma1 = 0.0164 on BOTH tensors    rank-1, a single-direction projection
  |cos| between the two recovered dirs = 1.0000   ONE shared direction
  ||delta||/||W|| = 1.42% and 1.41%         a gentle, consistent projection
  sink energy dim 3994 = 0.0000%            sink-clean; Heretic's was 6.18%

That is the Robinson in-band MTP abliteration, already applied, with a direction
that passes our sink screen outright. Nothing to do but preserve it, and the quant
carries it byte-identically. This is the configuration the entire Cold-Fusion
experiment was designed to test and never cleanly delivered.

The new format screen paid for itself on its first real use: think_prior.py on the
bf16 BEFORE any GPU time gave P(<think>) = 1.23e-06 at rank 52, against
Cold-Fusion stock 0.1850 and h300 0.2216. Roughly 150,000x cleaner.

Two durable findings about the pipeline itself:

The quant needs ~17 GB, not a whole card. It ran entirely in GPU1's spare 16 GB
with ZERO production seats stopped -- the h300 run's "stop BOTH GPU0 seats" was
never necessary, it simply had a free card by coincidence. The first attempt OOM'd
by 2.37 GiB at layer 64 of 65 with 3.57 GiB reserved-but-unallocated, which is
fragmentation, and PYTORCH_CUDA_ALLOC_CONF=expandable_segments:True closed it.

post_quant.py now builds a missing output index from the safetensors headers.
A sub-23 GB quant saves one bare shard with no index, and post_quant needs one;
this has broken three separate rounds and been hand-fixed every time. The header
is read by struct-unpacking the u64 length and parsing the JSON -- never
safe_open, which mmaps the whole 22 GB shard and ENOMEMs on ZFS.

Artifact verified: mixed-precision, 1968 tensors, 15 mtp, 333 visual, re:^mtp.*
present in the ignore list (llm-compressor pruned it as always), preproc restored.
Imatrix deferred per operator; the log confirms the usual uniform-MSE fallback, so
this build stays apples-to-apples with heresy's PPL 6.910.

persistent-memory.md

@@ -122,6 +122,15 @@ _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`
 
+- **🟡 ORCAROUTER QUANT BUILT AND VERIFIED 2026-08-21 01:24 — READY TO SERVE, NOT YET CUT OVER.** 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.
+  - **★ THE QUANT NEEDS ~17 GB, NOT A WHOLE CARD — and `PYTORCH_CUDA_ALLOC_CONF=expandable_segments:True` is what makes it fit.** Ran entirely on **GPU1's spare 16 GB with ZERO production seats stopped**; the h300 run's "stop BOTH GPU0 seats" was never necessary (it had a free card by coincidence). First attempt OOM'd by 2.37 GiB at layer 64/65 with **3.57 GiB reserved-but-unallocated** — pure fragmentation; `expandable_segments` closed it. ~7 min per attempt.
+  - **★ FIXED IN THE SCRIPT, after biting THREE rounds:** `post_quant.py` crashed with `FileNotFoundError: model.safetensors.index.json` because a sub-23 GB quant saves a single bare shard with no index. It now **builds the index from the safetensors headers** (`struct`-unpack the u64 length + parse the JSON — never `safe_open`, which mmaps 22 GB and ENOMEMs on ZFS). Previously hand-fixed each time and never in the script.
+  - ⚠ Quant dir written root/0600 **again** — normalized to `llmuser 0664`. Fourth time this session; worth fixing in `quant_mixed_nvfp4.py`. ⚠ `compare_mtp_head.py` prints a hardcoded "already measured at 47.7% acceptance" line on an IDENTICAL verdict — **stale text, not a measurement of this head.** ⚠ Imatrix deferred by operator (park id 42); the log confirms the usual `imatrix_mse … Falling back to uniform MSE`, so this build stays apples-to-apples with heresy's PPL 6.910.
+  - **⏭ NEXT: the acceptance/PPL/surface gate, then the cutover.** Rollback stays `.env.bak-coldfusion-L35-20260820` → heresy.
+
 - **⛔ COLD-FUSION ABANDONED — GEN SEAT ROLLED BACK TO `heresy` 2026-08-21 00:28 (operator directive).** The operator's call, made in advance of the result: *"If it's the base, we abandon h300 AND the base and chalk it up to a very powerful and useful learning experience. Our heretic methodology will definitely translate in the future."* The measurement came back **base**, so the condition fired.
   - **LIVE GEN SEAT = `/tank/aimodels/qwen38-27b-heresy-nvfp4-mixed`** (`MuXodious/Qwen3.8-27B-absolute-heresy` through our mixed NVFP4+FP8 recipe). Restored from `.env.bak-coldfusion-L35-20260820`; the h300 env is preserved at `.env.bak-h300-abandoned-20260821`. Verified: healthy, **KV 403,065 tok / 1.54× — its exact documented baseline**, 7/7 aliases 200, vision intact (red circle / blue square / green rectangle).
   - **★ The clincher: `<think>` is not even in heresy's top-20 first tokens (<0.002), against Cold-Fusion's 0.185.** That is a >100× gap — the two families are categorically different on this axis, and it is why no rollback *inside* Cold-Fusion (L35 or stock) would have helped.