Document raw Stage 2 and Stage 3 snapshots

README.md

@@ -40,6 +40,31 @@ per vehicle. The Stage 3 set contains the same 144-view grid for Nissan Patrol
 2021 under Town10HD_Opt/ClearNoon. Thirty-two clean views used earlier for Nissan
 mesh alignment are excluded from the released confirmation evaluation.
 
+## Raw snapshot layout
+
+| Hub path | Files | Exact bytes | Directory-manifest SHA-256 |
+| --- | ---: | ---: | --- |
+| `raw/stage2_town10_v1/` | 872 | 21,787,037,755 | `4ac82a74b0c9c8b0918b93b911997b12f6401f3cbd4b0c18914125e715faea67` |
+| `raw/stage3_nissan_patrol_2021_sealed_town10_v1/` | 148 | 3,631,182,409 | `89844aa31bd9ca1803b29bb2bddc5379dc8e3ad049c6e4448ce81fbc24dc5c3f` |
+
+Each directory has its own `SHA256SUMS`. The Stage 2 manifest covers 871
+payload files (864 samples and seven JSON records); the Stage 3 manifest covers
+147 payload files (144 samples and three JSON records). The checksum file itself
+is excluded from the corresponding manifest and is anchored by the table above.
+
+The immutable raw-data release is tagged `raw-v1-20260803`. For example, download
+only the Stage 2 snapshot with the repository utility:
+
+```bash
+python tools/huggingface_assets.py download /path/to/release \
+  --kind dataset \
+  --revision raw-v1-20260803 \
+  --allow 'raw/stage2_town10_v1/**'
+```
+
+Record the full commit resolved by the tag in experiment provenance rather than
+relying on the moving `main` branch.
+
 ## Sample format
 
 Each sample is a NumPy object array with seven ordered fields:
@@ -78,8 +103,8 @@ its sealed manifest SHA-256 is
 `05f30d781d083fc49ea1bbe7dfe861204f28911cecd31ba747e980e07e5db748`.
 
 These aggregate values use the project audit procedure recorded in the included
-provenance files. `SHA256SUMS` additionally verifies every file in this Hub
-release.
+provenance files. The two directory-level `SHA256SUMS` files additionally verify
+every payload file in the raw snapshots.
 
 ## Limitations and responsible use