Add metadata for batch 8

batch_8_metadata.json

@@ -0,0 +1,7 @@
+{
+  "upload_time": "2025-06-23T07:51:14.465162",
+  "total_trees": 121,
+  "new_trees": 8,
+  "batch_number": 8,
+  "upload_interval": 30
+}