Add shard_00021.manifest.json

manifests/shard_00021.manifest.json

@@ -0,0 +1,15 @@
+{
+  "shard_id": 21,
+  "rows": 135682,
+  "size_mb": 211.49,
+  "compression": "zstd",
+  "source_breakdown": {
+    "fineweb_edu": 0.5537,
+    "tiny_strange": 0.0893,
+    "cosmopedia_v2": 0.276,
+    "tiny_textbooks": 0.0296,
+    "mini_en": 0.0514
+  },
+  "created_at": "2026-06-27T09:26:08.260604Z",
+  "run_name": "bison-data-v2"
+}