enable garbage collection, openssh, autologin, etc.

also:
- mangohud
- flatpak
- wake on lan
- increase mic gain

global-home.nix

@@ -6,6 +6,12 @@
 }: {
   home.stateVersion = specialArgs.stateVersion;
 
+  nix.gc = {
+    automatic = true;
+    persistent = true;
+    dates = "Sun 05:00";
+  };
+
   home.packages = with pkgs; [
     bibata-cursors
     x264