vllm v0.30.0

# v0.30.0 ## Highlights This release features 762 commits from 315 contributors (104 new)! * **New models**: DeepSeek-V4.1-Flash (#56214, #56228, #56208) with the whole KV stored in MXFP8 through the FlashMLA V4.1 record on SM100 (#56893), DeepGEMM Mega-mHC (#56962), and async Engram prefetch with Engram DP sharding (#56512); DeepSeek-V4-Flash-Vision-Exp (#54566), also on ROCm (#55107) and with LoRA (#55897); GLM-5.3-Flash (#53906) with EPLB (#55119); K2-Horizon (#55063); Cohere Compass (#54774); Bailing V3 VL (#55921); Nanbeige4.2 via the Transformers backend (#56071); and a DeepSeek-V4 CPU backend with AVX512/AMX sparse MLA, indexer, mHC and compressor kernels (#55355). * **Fast Start**: a persistent per-GPU weight-cache daemon holds post-quantized, TP-sharded weights in GPU memory so restarting engines map them over CUDA IPC with instead of reloading from disk (#54921), now covering FP4 checkpoints (#55465) and multi-node TP (#55468). * **Watermarking**: Gumbel-max watermarked generation and detection with a keyed PRF, per-request opt-out and an example detection endpoint…