Add Qwen vision loading and Metal inference

src/engine/metal/qwen_mtplx/fused.rs

@@ -47,6 +47,7 @@ pub(super) fn operator(op: &Operation) -> Option<&'static str> {
             U::Rsqrt => "Rsqrt",
             U::Sin => "Sin",
             U::Cos => "Cos",
+            U::Erf => "Erf",
         },
         Operation::Binary(op) => match op {
             B::Equal => "Equal",