Add Intern-S2-Mobius (interns2_mobius) model

Hybrid Gated-DeltaNet / full-attention MoE with globally shared expert banks, fused gate/up SwitchGLU, and a guarded Metal router-topk kernel with a pure-MLX fallback.

Author: nightscape

ACKNOWLEDGMENTS.md

@@ -30,4 +30,5 @@ Added support for the following other features:
 - Tarjei Mandt: Added support for the following architectures: `Step 3.5 Flash`, 
 MoonshotAI's `Kimi K2.5`, Upstage's `Solar Open`, LG AI Research's `K-Exaone MoE`, 
 Meituan's `LongCat Flash Lite` Helped add support for the following model architectures: 
-Z.ai & THUKEG's `GLM5 (GLM MoE DSA)`
+Z.ai & THUKEG's `GLM5 (GLM MoE DSA)`
+- Martin Mauch: Added support for InternLM's `Intern-S2-Mobius`.