feat: update age configuration to be inside

flake.nix

@@ -0,0 +1,42 @@
+{
+  description = "Noisebell - door monitor system";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    agenix = {
+      url = "github:ryantm/agenix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+    pi-service.url = "path:./pi/pi-service";
+    remote.url = "path:./remote";
+    remote.inputs.nixpkgs.follows = "nixpkgs";
+  };
+
+  outputs = { self, nixpkgs, agenix, pi-service, remote }: {
+    nixosModules = remote.nixosModules;
+
+    nixosConfigurations.pi = nixpkgs.lib.nixosSystem {
+      system = "aarch64-linux";
+      modules = [
+        agenix.nixosModules.default
+        (import ./pi/module.nix {
+          pkg = pi-service.packages.aarch64-linux.default;
+          rev = self.shortRev or "dirty";
+        })
+        ./pi/configuration.nix
+        ./pi/hardware-configuration.nix
+      ];
+    };
+
+    nixosConfigurations.bootstrap = nixpkgs.lib.nixosSystem {
+      system = "aarch64-linux";
+      modules = [ ./pi/bootstrap.nix ];
+    };
+
+    devShells.x86_64-linux.default = let
+      pkgs = nixpkgs.legacyPackages.x86_64-linux;
+    in pkgs.mkShell {
+      packages = [ agenix.packages.x86_64-linux.default ];
+    };
+  };
+}