* llama-quant : fix quantizing 4D tensors
nrows_total was ne[1]*ne[2], so for a 4D tensor only the first ne[2]
slices were quantized and the rest of the rows were dropped. Use
ggml_nrows(tensor) to count all rows, including ne[3].
Fixes#29916
* llama-quant : detect expert tensors by name and fix imatrix size for 4D tensors
The MXFP4_MOE path used ne[2] > 1 to detect MoE expert tensors. This is
wrong for non-expert tensors with 3 or more dims, e.g. MLA projections
(BailingMoE3) and 4D conv kernels. Use the tensor name instead: all
tensors used by GGML_OP_MUL_MAT_ID are named *_exps or *_chexps. This
also removes the BailingMoE3 special case.
The imatrix holds one vector of ne[0] values per 2D slice, so the
expected size is ne[0]*ne[2]*ne[3], not ne[0]*ne[2]. This matches how
the imatrix is indexed per row for 4D tensors in llama_tensor_quantize_impl.
Assisted-by: Claude Opus 5.5