fix(VT-FP8-QUANT-ARCH-GATE): register QuantFp8Static from an unconditional CUDA TU (#960)

.agents/issue-index.md

@@ -301,3 +301,5 @@ rather than merged. `scripts/check-agent-record.py` gates both.
 | [#1049](https://github.com/mudler/vllm.cpp/issues/1049) | — | `Ltx2Guidance` (`src/vllm/model_executor/models/ltx2_pipeline.cpp:526 @ c1fe35592`) is dead in production: `git grep -n 'Ltx2Guidance(' -- src include examples tests` returns the declaration (`ltx2_pipeline.h:330`), the definition, and ONE call, at `tests/vllm/models/test_ltx2_pipeline.cpp:710`. It is also the only path to two ported guiders — `Ltx2CfgDelta` (`ltx2_pipeline.cpp:532`, plus `test_ltx2_pipeline.cpp:615`) and `Ltx2StgDelta` (`:534`, plus `:630`) — so both are reachable from no product entry point either. `Ltx2BatchedPerturbationConfig` (`ltx2_pipeline.h:380`) is the same shape from a different direction: constructed only at `test_ltx2_pipeline.cpp:832-859`, while the LTX-2.5 text-to-audio path perturbs through `Ltx2DitPerturbation`, a different type, and no other path perturbs at all. This is the test-only-driver shape [`reachability.md`](reachability.md) names. All four landed with #641. `Ltx2MultiModalGuidance` was the fourth member of the set and is no longer one: [#1005](https://github.com/mudler/vllm.cpp/issues/1005) gave it a production call site in `ltx2_t2a.cpp`. Closing this means either routing a product path through `Ltx2Guidance` with a configured `Ltx2GuiderKind` — `Ltx2GuiderSigmaBin` and `Ltx2GuiderParamsForSigma` are already ported beside it — or retiring the unreached arms into `.agents/completed/` with their provenance. Found repairing the fresh review of [#1039](https://github.com/mudler/vllm.cpp/issues/1039) on PR [#1032](https://github.com/mudler/vllm.cpp/pull/1032), where an earlier draft of that row's spec §6b claimed the row ended all four test-only drivers; §6b now carries the measured table. Listed under `## Owed` in [`ltx25-t2a-one-stage.md`](specs/ltx25-t2a-one-stage.md) | bug |
 | [#1050](https://github.com/mudler/vllm.cpp/issues/1050) | — | The guider rescale's `std` comment states a consequence that cannot exist. `src/vllm/model_executor/models/ltx2_pipeline.cpp:505-506 @ c1fe35592`, repeated at `include/vllm/model_executor/models/ltx2_pipeline.h:319-322`, says torch's `std` is the UNBIASED (N-1) estimator by default and "the biased one would be a small, everywhere, resolution-dependent gain error that no shape or finiteness check can see". `factor_raw` is `unbiased_std(cond) / unbiased_std(pred)`, two `std`s over the SAME `count`, so the divisor cancels exactly: `sqrt(ss_c/(n-1))/sqrt(ss_p/(n-1)) == sqrt(ss_c/ss_p) == sqrt(ss_c/n)/sqrt(ss_p/n)`. There is no gain error, small or otherwise, and nothing about it is resolution-dependent; the two forms differ only by f32 rounding in the divide. Worth a record rather than a silent correction because the comment tells the next reader a gate is needed there and it is not: the fresh review of [#1039](https://github.com/mudler/vllm.cpp/issues/1039) mutated the estimator to the biased form and it survived — correctly, because it is an IDENTITY — and a survivor at that site otherwise reads as a blind instrument and costs another investigation. The CODE is right as written and should stay `unbiased_std`, because the name is what mirrors torch even where the ratio does not care; the COMMENT is the defect. Pre-existing from `cefacd2d0` (#641). Found repairing that review on PR [#1032](https://github.com/mudler/vllm.cpp/pull/1032) and out of scope there under its explicit exclusions. Listed under `## Owed` in [`ltx25-t2a-one-stage.md`](specs/ltx25-t2a-one-stage.md) | bug |
 | [#1052](https://github.com/mudler/vllm.cpp/issues/1052) | — | `tests/vllm/v1/test_engine_core_proc.cpp:481` ("EngineCoreProc: immediate shutdown aborts in-flight requests") searches for the abort frame over a FIXED budget of 1000 dequeues while a `max_tokens=100000` request keeps the busy loop producing token deltas, so nothing bounds how many frames precede the abort and the budget is a bet on scheduling. MEASURED at `37e680cab`, same binary throughout, CPU-only Release on 20 cores: **2 failures in 3 `ctest -j4` runs** of the full 492-test suite (`CHECK( abort_seen ) is NOT correct!`), **0 in 25 solo runs** on an idle box at load 3.34, **0 in 25 solo runs against 20 spinning processes**, and 0 in two `ctest -R '^test_engine_core_proc$'` runs (`Passed 0.03 sec`). So CPU pressure alone does not reproduce it; it needs the `-j4` harness. The third `-j4` run failed `test_cpu_threadpool` INSTEAD, which is on the same load-dependent list, so the IDENTITY of the failing test rotates between runs of an unchanged binary and both pass alone with exit 0. NO ISSUE NAMED THIS TEST: PR [#1032](https://github.com/mudler/vllm.cpp/pull/1032)'s body attributed its flake to [#294](https://github.com/mudler/vllm.cpp/issues/294), which is a different defect in a different test (`test_async_llm` reusing an aborted request id), and a misattributed flake is worse than an untracked one because the next reader checks the citation, finds an open issue about something else, and stops looking. The assertion guards a real guarantee (an in-flight request gets a `kAbort` finish on immediate shutdown); the 1000-frame budget is the part that is a guess. Found repairing the fresh review of [#1039](https://github.com/mudler/vllm.cpp/issues/1039), on a branch that touches no file under `tests/vllm/v1/` or `src/vllm/v1/`. Listed under `## Owed` in [`ltx25-t2a-one-stage.md`](specs/ltx25-t2a-one-stage.md) | bug |
+| [#960](https://github.com/mudler/vllm.cpp/issues/960) | `MODEL-TEXT-nemotron-h-nemotron-hfor-causal-lm` | `vt::QuantFp8Static`'s ONLY CUDA registration lived at `src/vt/cuda/cuda_matmul_fp8_cutlass.cu:376` (@ `0e1bee42f`), and `CMakeLists.txt:1668` compiles that translation unit only when `VT_CUTLASS_FP8_ARCHS` is non-empty — yet the kernel body has ZERO cutlass tokens (`:353-370`): it is `out[i] = e4m3(x[i] * (1/input_scale))`, a grid-stride elementwise convert. So on every CUDA arch outside the cutlass-fp8 cell — sm_110/Thor is the measured one, and `cutlass-fp8: DISABLED for [110]` is that arch's DOCUMENTED NORMAL PROFILE, not a misconfiguration — `OpId::kQuantFp8Static` was not registered for `DeviceType::kCUDA` at all. Nothing refused first: the GEMM partner `kMatmulFp8CublasLt` IS registered unconditionally (`src/vt/cuda/cuda_matmul.cu:920`), so `MatmulFp8CutlassD`'s guard passed, and the missing quant then resolved through `src/vt/op_provider.cpp:501` to the portable CPU reference tier — eligible because `CudaBackend::UnifiedMemory()` is true — which dereferenced DEVICE pointers on the host and SIGSEGV'd one call later under a banner reading "correct but slow". Fixed by relocating the registration to a new unconditionally-compiled TU `src/vt/cuda/cuda_quant_fp8.cu`, which restores upstream's own partition (vLLM builds `static_scaled_fp8_quant` from the unconditional `VLLM_EXT_SRC` list and gates only its cutlass `scaled_mm` sources). This removes one live INSTANCE of [#844](https://github.com/mudler/vllm.cpp/issues/844) and does not address its class, which stays open. Unblocks the FP8 W8A8 arm on every non-cutlass CUDA arch — the base [#810](https://github.com/mudler/vllm.cpp/issues/810)/[#517](https://github.com/mudler/vllm.cpp/issues/517) A2-Q1 needs, where 46 FP8 mamba projections are 36.6% of decode bytes. Spec [`vt-fp8-quant-arch-gate.md`](specs/vt-fp8-quant-arch-gate.md) | bug |
+| [#989](https://github.com/mudler/vllm.cpp/issues/989) | `VT-FP8-QUANT-ARCH-GATE` | `scripts/check-pr-size.py`'s `classify_path` has no entry for `.agents/reachability.md` (added by `POLICY-NOTHING-LANDS-DEAD`, [#888](https://github.com/mudler/vllm.cpp/issues/888) @ `8f49ac3be`), and it FAILS CLOSED, so `pr-size` — a REQUIRED check — refuses every pull request that touches that guide, and `tests/scripts/test_check_pr_size.py` has been red on `main` ever since. Red SILENTLY: that suite is wired into no CI job and is not in `agent-preflight.sh`'s `SUITES`, so the only thing that ever loads it is `check-pr-size`'s own executable-evidence contract, which fires only when a PR edits a checker — the red is reachable exclusively by the next person who must touch that file, and presents to them as their own breakage (the [#584](https://github.com/mudler/vllm.cpp/issues/584)/[#965](https://github.com/mudler/vllm.cpp/issues/965) shape). Third instance of the class after [#856](https://github.com/mudler/vllm.cpp/issues/856) (`issue-index.md` + the style guides) and [#668](https://github.com/mudler/vllm.cpp/issues/668) (`.agents/oracles/*`), both fixed in flow by the row that tripped over them. FIXED IN FLOW while landing [#960](https://github.com/mudler/vllm.cpp/issues/960), which could not register its new checker's creation mutation without touching `check-pr-size.py` at all. NOT fixed: wiring that suite into CI, which is its own change and would red `main` until this landed | bug |