docs: acaua mirror model card with code+weights provenance

docs: add Apache-2.0 LICENSE per s4(a)

config: mirror metadata (keypoint schema + bundled detector pairing)

docs: add NOTICE attribution per Apache-2.0 s4(d) (code AND weights)

weights: pure-PyTorch port of mmpose RTMPose-tiny (COCO 17-kp), converted from upstream rtmpose-tiny_simcc-aic-coco_pt-aic-coco via scripts/convert_rtmpose.py

initial commit