Add shard_00015.manifest.json

manifests/shard_00015.manifest.json

@@ -0,0 +1,15 @@
+{
+  "shard_id": 15,
+  "rows": 133145,
+  "size_mb": 211.8,
+  "compression": "zstd",
+  "source_breakdown": {
+    "fineweb_edu": 0.5614,
+    "tiny_strange": 0.0899,
+    "cosmopedia_v2": 0.281,
+    "mini_en": 0.0288,
+    "tiny_textbooks": 0.0389
+  },
+  "created_at": "2026-06-27T09:14:08.876112Z",
+  "run_name": "bison-data-v2"
+}