Function lora_experts_env 

pub fn lora_experts_env() -> bool

Feature-1 (MoE expert + router LoRA) master switch. ATLAS_LORA_EXPERTS=1 (or true) opts INTO loading + applying routed-expert / router deltas. DEFAULT OFF: an adapter that targets mlp.experts.* / mlp.gate is a NAMED reject at load unless this is set, so the base path stays byte-identical and the (correctness-first, host-synced, non-graphable) expert side-path is never silently on. Read once.