loki: Several tweaks

- Disable libvirtd
- Explicitly enable DHCP on enp4s0
- Disable ssh-agent
- Add gamemode

machines/loki/configuration.nix

@@ -46,7 +46,7 @@
       enable = true;
       sway = true;
     };
-    libvirtd.enable = true;
+    libvirtd.enable = false;
     livebook = {
       enable = false;
       dataDir = "/home/erwin/workspace/livebook";
@@ -179,7 +179,13 @@
 
     networks = {
       "40-enp4s0" = {
-        DHCP = "yes";
+        matchConfig = {
+          Name = "enp4s0";
+        };
+
+        networkConfig = {
+          DHCP = "yes";
+        };
       };
       "40-wghorus" = {
         matchConfig = {
@@ -245,12 +251,25 @@
   };
 
   services.openssh.enable = true;
-  programs.ssh.startAgent = true;
+  # programs.ssh.startAgent = true;
 
   services.envfs.enable = true;
   services.cpupower-gui.enable = true;
   services.tailscale.enable = true;
 
+  programs.gamemode = {
+    enable = true;
+    settings = {
+      general = {
+        renice = 5;
+      };
+      custom = {
+        start = "${pkgs.libnotify}/bin/notify-send 'GameMode started'";
+        end = "${pkgs.libnotify}/bin/notify-send 'GameMode ended'";
+      };
+    };
+  };
+
   services.sunshine = {
     enable = true;
     user = "erwin";