[Docs] Clarify Hunyuan expert remapping scope

Signed-off-by: hsliuustc0106 <liuhongsheng4@huawei.com>

tests/model_executor/models/test_kv_cache_scale_mapper.py

@@ -97,7 +97,7 @@ def test_model_loaders_do_not_call_removed_get_cache_scale(rel_path: str) -> Non
         ),
     ],
 )
-def test_hunyuan_expert_mapping_uses_vllm_public_contract(
+def test_hunyuan_expert_mapping_separates_public_and_local_contracts(
     module_name: str,
     class_name: str,
     monkeypatch: pytest.MonkeyPatch,