automatic overlay for ./packages directory

also gamescope added system-wide and in flatpak for steam

hosts/takamaki/configs/flatpak.nix

@@ -22,6 +22,7 @@
       }
       "com.valvesoftware.Steam"
       "org.vinegarhq.Sober"
+      "org.freedesktop.Platform.VulkanLayer.gamescope//25.08"
     ];
     update.auto = {
       enable = true;