fix(kavita): move libraries to /var/lib/libraries

Previously we had our libraries in a subdirectory of /var/lib/copyparty

While that's an OK idea in theory, in practice it'd require us to make
every directory on the way to /var/lib/copyparty/data/groups/library
+rx to kavita. That's something we're unwilling to do. The true fix is
to move this out so we don't have to meddle with permissions except
those which are directly on this directory

packetmix/systems/teal/copyparty.nix

···
             };
           };
           "/groups/library" = {
-            path = "/var/lib/copyparty/data/groups/library";
+            path = "/var/lib/libraries";
 
             access = {
               A = [
···
             builtins.attrValues
             (map (mount: mount.path))
             (map (lib.removePrefix "/var/lib/"))
+            (builtins.filter (name: !(builtins.elem name ["libraries"]))) # For shared directories we can't afford for systemd to change permissions on us...
             (lib.concatStringsSep " ")
           ]);
       };
···
 
     clicks.storage.impermanence.persist.directories = [
       "/var/lib/copyparty"
+      {
+        directory = "/var/lib/libraries";
+        mode = "0770";
+        group = "copyparty+kavita";
+        defaultPerms = {
+          mode = "0770";
+          group = "copyparty+kavita";
+        };
+      }
     ];
   };
 }