add examples and test VM

flake.nix

@@ -1,13 +1,50 @@
 {
-  description = "Panoptikon - Website and command output monitoring";
+  description = "Panoptikon – Watch the world from NixOS";
 
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
   };
 
-  outputs = inputs: {
-    nixosModules.default = ./module.nix;
-    overlays.default = ./overlay.nix;
-  };
-}
+  outputs =
+    inputs:
+    let
+      eachSupportedSystem = inputs.nixpkgs.lib.genAttrs inputs.nixpkgs.lib.systems.flakeExposed;
+      inherit (inputs.nixpkgs) lib;
+    in
+    {
+      nixosModules.default = import nix/module.nix;
+      overlays.default = import nix/overlay.nix;
 
+      apps = eachSupportedSystem (
+        system:
+        let
+          nixosSystem = lib.nixosSystem {
+            system = "x86_64-linux";
+            modules = [
+              inputs.self.nixosModules.default
+              {
+                nixpkgs.overlays = [ inputs.self.overlay ];
+              }
+              {
+                virtualisation.vmVariant = {
+                  virtualisation.graphics = false;
+                };
+                services.getty.autologinUser = "root";
+                system.stateVersion = lib.trivial.release;
+              }
+              ./examples/simple.nix
+              ./examples/bitcoin.nix
+              ./examples/nixos.nix
+              ./examples/system.nix
+            ];
+          };
+        in
+        {
+          panoptikon-vm = {
+            type = "app";
+            program = lib.getExe nixosSystem.config.system.build.vm;
+          };
+        }
+      );
+    };
+}