Function moe_swiglu_batch_encode 

pub fn moe_swiglu_batch_encode(
    encoder: &mut CommandEncoder,
    registry: &mut KernelRegistry,
    device: &DeviceRef,
    gate_up: &MlxBuffer,
    output: &MlxBuffer,
    intermediate: usize,
    top_k: usize,
) -> Result<()>

Encode a batched SwiGLU across all top_k expert slots in one dispatch.

Takes a [top_k, 2*intermediate] gate_up buffer and produces [top_k, intermediate] output: GELU(gate[i]) * up[i] per slot.

Replaces top_k separate moe_swiglu_fused_encode_offset dispatches with 1.

Arguments

• encoder – Command encoder to record into.
• registry – Kernel registry for pipeline lookup.
• device – Metal device reference.
• gate_up – f32 buffer [top_k * 2 * intermediate].
• output – f32 buffer [top_k * intermediate].
• intermediate – Intermediate dimension per expert.
• top_k – Number of selected expert slots.