configs: drop the stockholm krebs, sitemap, ssl and acl modules
krebs.enable and krebs.sitemap were unused. krebs.ssl only trusted the
krebs intermediate CA, which expired on 2026-06-29, so that trust
validated nothing.
radio's playlist ACLs move from krebs.acl (setfacl -R at boot) to
systemd-tmpfiles: rwx on the playlist directory, default ACLs on its
tree so new files get rw and new directories rwx, and traverse on the
parents for lass. Existing content keeps the ACLs it already has; X is
avoided because tmpfiles applies it to existing files with an r-- mask.