SOLIDSHARE_CONTAINER_NAME
Pod-relative paths used by the sharing feature.
SHARES_CONTAINER_NAME holds private bookkeeping (given/received indexes). Owner-only ACL. Kept under SOLIDSHARE_CONTAINER_NAME rather than a dot-prefixed root path because Community Solid Server reserves the
/.*namespace for server-internal resources and rejects any access to it with 403ForbiddenHttpError.