back-fill arXiv ID 2604.21668

README.md

@@ -25,7 +25,7 @@ Data release for **"Encoder-Free Human Motion Understanding via Structured Motio
 - 🌐 **Project page:** https://yaozhang182.github.io/motion-smd/
 - 💻 **Code:** https://github.com/yaozhang182/motion-smd
 - 🤗 **LoRA adapters:** https://huggingface.co/zyyy12138/motion-smd-lora
-- 📄 **Paper (arXiv):** `arXiv:ARXIV_ID_TBD` (to appear)
+- 📄 **Paper (arXiv):** https://arxiv.org/abs/2604.21668
 
 ---
 
@@ -95,7 +95,7 @@ in each subdir.
 @article{zhang2026smd,
   title   = {Encoder-Free Human Motion Understanding via Structured Motion Descriptions},
   author  = {Zhang, Yao and Liu, Zhuchenyang and Ploetz, Thomas and Xiao, Yu},
-  journal = {arXiv preprint arXiv:ARXIV_ID_TBD},
+  journal = {arXiv preprint arXiv:2604.21668},
   year    = {2026}
 }
 ```