Add metadata for batch 13

batch_13_metadata.json

@@ -0,0 +1,7 @@
+{
+  "upload_time": "2025-06-23T07:54:15.901587",
+  "total_trees": 159,
+  "new_trees": 9,
+  "batch_number": 13,
+  "upload_interval": 30
+}