Major config overhaul: use custom modules, setup for multi-host config, and less boilerplate

modules/system/virtualization/virtual-machines/default.nix

@@ -0,0 +1,23 @@
+{ lib, config, pkgs, ... }:
+
+let cfg = config.systemSettings.virtualization.virtualMachines;
+in {
+  options = {
+    systemSettings.virtualization.virtualMachines = {
+      enable = lib.mkEnableOption "Enable qemu virtual machines, distrobox, and waydroid";
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    environment.systemPackages = with pkgs; [ virt-manager distrobox ];
+    virtualisation.libvirtd = {
+      allowedBridges = [
+        "nm-bridge"
+        "virbr0"
+      ];
+      enable = true;
+      qemu.runAsRoot = false;
+    };
+    virtualisation.waydroid.enable = true;
+  };
+}