Try Claude branch of possum to fix Windows CI

diff --git a/storage/possum/lib b/storage/possum/lib
index f98395b5aa36067cb8543f32a0b493a5893bf265..20486a2982cab406fdfc302a5547d5b2cffb0000 160000 (submodule)
--- a/storage/possum/lib
+++ b/storage/possum/lib
@@ -1 +1 @@
-Subproject commit f98395b5aa36067cb8543f32a0b493a5893bf265
+Subproject commit 20486a2982cab406fdfc302a5547d5b2cffb0000