* apply gating in recurrent_gated_delta_rule * update cache with new state * prealocate outputs in recurrent_gated_delta_rule * feat(kernel): gated-delta kernel scaffolding with CPU fallbacks and tests; integrate in Qwen3Next behind flag * feat(kernel): implement Metal kernel for gated delta prefill with time iteration to optimize performance * faster single time step kernel * use kernel for prefill * version bump --------- Co-authored-by: Goekdeniz-Guelmez <[email protected]> Co-authored-by: Awni Hannun <[email protected]>