Granite 4.1-3B / Vulkan RADV native PP512/TG128

User reports Granite-4.1-3B at 88.7 t/s generation and 2278 t/s prompt processing on an AMD Strix Halo 128GB system with a single Radeon 8060S iGPU. Setup is llama.cpp with UD-Q4_K_XL, full offload, batch 2048 and flash attention, using the RADV Vulkan backend. The figures are separate llama-bench pp512 and tg128 microbenchmarks, not one end-to-end request; the same GPU reached 88.1 t/s generation under AMDVLK and 2323 t/s prompt processing under ROCm, with no ROCm generation figure published.