PLENA Compiler

MoE code organization

• aten/plena/program_routed_moe.py contains reusable routed-MoE lowering helpers: router logits, V_TOPK selection, dynamic expert-weight addressing, routed gather/scatter, expert activation, and combine.
• aten/models/gpt_oss/ contains GPT-OSS-specific reference semantics and real-checkpoint loading utilities used to validate that substrate.
• ISA, assembler, and hardware documentation remain in assembler/ and doc/.