manatee: Wait for ZFS mounts before starting sandboxed /mnt/media services

hosts/manatee/modules/navidrome/default.nix

@@ -37,5 +37,11 @@ in
         };
       };
     };
+
+    # `MusicFolder` is bind mounted into the service's own mount namespace when it
+    # starts, so starting before the ZFS dataset is mounted leaves it with an empty folder
+    systemd.services.navidrome = lib.mkIf navidromeEnabled {
+      unitConfig.RequiresMountsFor = [ config.services.navidrome.settings.MusicFolder ];
+    };
   };
 }