memory: RP-seat direction — keep MeroMero, reject Artemis, Dark-Scarlett 3.8 queued as the MTP-restoring move

persistent-memory.md

@@ -131,6 +131,8 @@ _As of 2026-08-15 — **GEN SEAT REQUANTED (mixed NVFP4+FP8, +18% decode / prefi
 
 ## Recent decisions
 
+- `[2026-08-15]` **RP-seat direction: KEEP MeroMero on `char-rp`; Artemis-31B rejected; next move is Dark-Scarlett on a Qwen3.8 base when it lands (operator).** Evaluated `TheDrummer/Artemis-31B-v1.1` — mechanically a drop-in (same `google/gemma-4-31B-it` base, identical 1188-tensor/356-vision census, same missing-`preprocessor_config.json` trick), so it's purely a quality call, and our own survey already ranked MeroMero **#1** vs Artemis **#6**; Artemis is also unlicensed and its author deprioritizes correctness + warns of token-banning-for-stability, which fights char-rp's tool-calling requirement. **MTP verified impossible on both** (Gemma-4 has no MTP head at all — base/MeroMero/Artemis are all MTP=0; no finetune can add one). **But speculative decoding IS reachable on a Gemma-4 seat via a DETACHED drafter** — vLLM 0.24 supports `eagle3` + `gemma4_mtp`, and real drafters exist: `google/gemma-4-31B-it-assistant` (0.94 GB, 4-layer, 761K dl), `RedHatAI/gemma-4-31B-it-speculator.eagle3` (4.47 GB), `AEON-7/…eagle3-NVFP4` (3.53 GB). ⚠ all list their verifier as **stock** gemma-4-31B-it, not an RP finetune, so acceptance against MeroMero is unmeasured and likely well below the gen seat's ~48%. UNTESTED — parked, ~45 min to measure, needs GPU0 headroom (card is at 94.4/97.9 GB). **Why the Dark-Scarlett 3.8 plan is the strong one:** DS is Qwen3.6-based today, so a 3.8 respin lands on the *gen seat's* architecture → native MTP returns and the whole mixed NVFP4+FP8 recipe + graft ports directly. Watch two things on arrival: `from_pretrained` **silently drops MTP heads during finetuning** (verify 15 `mtp.*` tensors in the index; graft from stock if absent), and DS v1.0 required the `Qwen3_5ForConditionalGeneration` **wrapper class** to save a config vLLM/SGLang accept. Both in `docs/pfi/model-quantization-playbook.md`.
+
 - `[2026-08-15]` **Quant lessons consolidated into `docs/pfi/model-quantization-playbook.md` — the durable home; read it BEFORE any requant.** Survey found quant knowledge scattered across 18 files in 4 trees, with **three** documents having independently written overlapping "landmines" sections (the loader-class trap alone was rediscovered 3×). Playbook owns the **transferable** lessons (scheme choice, landmines, acceptance gate + its 3 measurement traps, hardware/co-residency); per-model artifacts are demoted to worked examples that link up. Carries a **superseded-claims table** — which immediately earned itself: the heretic2 runbook's "use modelopt, compressed-tensors can't load the BF16 MTP" is **false** (the cause was the missing `re:^mtp.*` ignore, not the format) and would have sent the next session down the modelopt dependency-hell path; that runbook now carries a stale-warning header. Maintenance rule in `CLAUDE.md`: model-agnostic → playbook, model-specific → stays put, wrong claim → dated superseded row, never a silent edit. Motivated by Qwen3.8 having just released — the next model swap needs a requant. Commit `a91cc3f`.
 
 - `[2026-08-15]` **Operator ruling: the gen seat's +1.7% perplexity is an acceptable price for the speed — SETTLED, don't re-litigate.** Precise attribution for future reasoning: it is the **activation-quantization** cost (W4A4 MLPs + FP8 attention vs BF16 activations), not an MTP cost — PPL was measured with speculative decoding **off** on both builds, so MTP was not in the loop. Turning MTP off would not recover it; only reverting the quant would (rollback = one `.env` line, old build intact at `…/qwen38-27b-uncensored-nvfp4`).