Scattermoe LoRA optimizations (#3513)

* optimize moe + lora

* more scattermoe optims

* selective dequant

* add correctness unit tests and benchmarks for scattermoe + lora

* handle base+lora split kernel for older moe models

* chore: lint

* fix casting for H200 and B200

* register pressure estimation and pruning for h200/b200

* use soft limit for pruning

* qkv patch for qwen3.5moe

* support text_model for qwen3.5 moe

* nesting of qwen3

* use udpated cce with zero3 support

* Fix decomposed backward for QKV and O projections

eliminates B @ A materialization in LoRA attention backward, replacing full [out, in] matmuls with two small [T, R] matmuls.

scripts/cutcrossentropy_install.py

@@ -29,5 +29,5 @@ UV_PREFIX = "uv " if USE_UV else ""
 
 print(
     UNINSTALL_PREFIX
-    + f'{UV_PREFIX}pip install "cut-cross-entropy[transformers] @ git+https://github.com/axolotl-ai-cloud/ml-cross-entropy.git@fa9a7fe"'
+    + f'{UV_PREFIX}pip install "cut-cross-entropy[transformers] @ git+https://github.com/axolotl-ai-cloud/ml-cross-entropy.git@63b15e6"'
 )