Fix expected output for window count test

Change avg_size from 20.0 to 20 to match actual SQLite output.

Author: claude

test/assets/expected/window-select/google/disks/text/disks-window-count.csv

@@ -1,7 +1,7 @@
 name,sizeGb,total,avg_size
-demo-disk-qq1,10,6,20.0
-demo-disk-qq2,10,6,20.0
-demo-disk-xx2,10,6,20.0
-demo-disk-xx3,20,6,20.0
-demo-disk-xx4,30,6,20.0
-demo-disk-xx5,40,6,20.0
+demo-disk-qq1,10,6,20
+demo-disk-qq2,10,6,20
+demo-disk-xx2,10,6,20
+demo-disk-xx3,20,6,20
+demo-disk-xx4,30,6,20
+demo-disk-xx5,40,6,20