…ntizedModel

Per qwen3-moe-forward-v1 v1.2.0 (M32c.2.2.2.1 integration strategy, PR #1123),
this is the per-token forward pass for Qwen3-MoE-arch GGUF models. Mirrors
`OwnedQuantizedModel::forward` step-for-step except the FFN site, which
calls M32c.2.2.2.0's `moe_ffn_forward_layer` instead of the dense
SwiGLU/GELU dispatch.

WHAT THIS PR SHIPS
==================
* `crates/aprender-serve/src/gguf/inference/forward/forward_qwen3_moe.rs`
  (NEW): impl block on `OwnedQuantizedModel` adding
  `forward_qwen3_moe(token_ids, moe_layers, num_experts,
  num_experts_per_tok, moe_intermediate, data) -> Result<Vec<f32>>`.
  Reuses existing `&self` methods for embedding, attention norm,
  qkv_matmul, RoPE (apply_rope), causal_attention, attn_output proj,
  output_norm, and lm_head — ZERO duplication of attention code. The
  ONLY new logic is the per-position FFN call to `moe_ffn_forward_layer`.

* `crates/aprender-serve/src/gguf/inference/forward/mod.rs`: register
  the new module.

* `crates/aprender-serve/tests/qwen3_moe_forward_one_token.rs` (NEW):
  F-QW3-MOE-C22211-001 — full 1-token forward against the cached
  17.3 GB Qwen3-Coder GGUF. Asserts:
    - logits.len() == vocab_size (151936)
    - all logits finite (no NaN/Inf)
    - argmax in valid range
  Skipped when no GGUF cached (slow live test; runs minutes per call
  due to mmap fault-in + 48 layers × 128-expert routing × top-8 ×
  per-expert Q4_K/Q6_K matmul).

WHY THIS DESIGN (PER v1.2.0)
============================
Three integration approaches were considered (see contract):
  (A) Add fields to OwnedQuantizedModel: 99-site blast radius.
  (B) Parallel run_qwen3_moe_generate function: ~300 LOC + helpers.
  (C) Wrapper struct: ~150 LOC + helpers.

The chosen path is a HYBRID of (B) and (C): a method on
OwnedQuantizedModel that reuses existing `&self` primitives (no
duplication, no new struct) and takes mmap data + moe_layers as
PARAMETERS (no field add, no 99-site touch). Strictly less work
than the originally planned (B) while preserving the
"CI-must-stay-green" invariant.

WHAT M32c.2.2.2.1.2 (NEXT PR) WILL SHIP
========================================
* `run_qwen3_moe_generate(mapped, tokens, gen_config, config)`:
  full inference loop calling forward_qwen3_moe per token, sampling,
  detokenizing — sibling to `run_gguf_generate`.

WHAT M32c.2.2.2.1.3 WILL SHIP
==============================
* Dispatch flip in `run_inference`: arch == "qwen3_moe" routes to
  run_qwen3_moe_generate. Removes M32c.2.1's gguf_gpu_generate.rs
  short-circuit.

WHAT M32c.2.2.2.1.4 WILL SHIP
==============================
* Live falsifier — `apr run <qwen3-coder>.gguf -p "Hi" -n 8`
  exits 0 + stdout matches /\\S/. Discharges
  FALSIFY-QW3-MOE-FORWARD-003.

NO BEHAVIOR CHANGE in this PR. The new method is additive; existing
forward path is untouched. Compilation clean.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>