Overview llama.cpp 0.4.1 adds Maple 20B-A1B, Tencent Hy 4, and Spark2.5 support, improves JSON schema handling, chat parsing, logging, and server child-process management, and updates ggml to v0.24.0. API changes Changed `llama_sampler_chain_n()` to return `int32_t` instead of `int` (#28631). Added `server_subproc` and `waiter` for router child-process monitoring in `server-common.h` (#28555). New models Added Maple 20B-A1B ternary MoE architecture (CPU) (#27000). Added Tencent Hy 4 (`hy_v4`) preview architecture support (#28127). Added Spark2.5 support (#27868). Core changes Added Kimi-K3 recurrent-state rollback support (#28466).

Fixed MTP context KV cache allocation for DeepSeek2, GLM-MoE, and related models (#28630). Fixed GDN normalization from `max` to `rsqrt` for affected Qwen/Kimi/GLM models (#28068). Fixed Granite parameter counts and Granite3 MoE unknown parameter counts (#28643, #28632). Fixed MIMO2 SWA pattern loading and incorrect `get_key_or_arr` uses (#28865, #28868). Added `--fuse-qkv` conversion flag to fuse Q/K/V tensors during HF-to-GGUF conversion (#22780). Wrote explicit `recurrent_layers` metadata for Qwen3-Next/Qwen3.5 conversion (#28208). Refactored JSON…