Rewrites V2_PORTING_STATUS.md to reflect completion: the scope is now ALL fastvideo models (not Wan+LTX-2 only). Documents the self-contained recipe-package porting mechanism (ComponentSpec.adapter), the 15 net-new architectures + 5 Wan-family variants newly ported (CPU-verified end-to-end; GPU=BRINGUP), the 7 GPU-verified models, and the single env-blocked id (VSA-14B, needs nvcc).