Update split restore instructions

README.md

@@ -21,13 +21,22 @@ and post-shuffle order SHA-256
 
 ## Restore
 
-Every `.tar` file is independently extractable. From the intended project root:
+All payload archives are independently extractable except
+`s1_spar_234k_media_03.tar`, which is transported as four byte-exact parts to
+avoid a large-file metadata timeout. Reassemble and verify it first:
 
 ```bash
+cat s1_spar_234k_media_03.tar.part{00..03} > s1_spar_234k_media_03.tar
+sha256sum -c s1_spar_234k_media_03.original.sha256
+```
+
+Then, from the intended project root:
+
+```bash
+sha256sum -c MANIFEST.sha256
 for archive in /path/to/download/*.tar; do
   tar -xf "$archive"
 done
-sha256sum -c MANIFEST.sha256
 ```
 
 Extraction reconstructs the expected `ckpts/` and `data/` paths. In particular, the LLaVA-Hound media archive materializes the legacy paths required by the original S1 annotation under `data/media/llava_hound/frames/`.