introduce nix and flakes

flake.nix

@@ -0,0 +1,87 @@
+{
+  description = "devx - A tool for generating, validating & sharing all your configurations";
+
+  inputs.nixpkgs.url = "nixpkgs/nixos-25.05";
+
+  outputs =
+    { self, nixpkgs }:
+    let
+      supportedSystems = [
+        "x86_64-linux"
+        "x86_64-darwin"
+        "aarch64-linux"
+        "aarch64-darwin"
+      ];
+      forAllSystems = nixpkgs.lib.genAttrs supportedSystems;
+      nixpkgsFor = forAllSystems (system: import nixpkgs { inherit system; });
+    in
+    {
+      packages = forAllSystems (
+        system:
+        let
+          pkgs = nixpkgsFor.${system};
+          version = "v0.4.39";
+        in
+        {
+          default = pkgs.buildGoModule {
+            inherit version;
+            pname = "devx";
+            src = pkgs.fetchFromGitHub {
+              owner = "stakpak";
+              repo = "devx";
+              rev = version;
+              sha256 = "sha256-uvDWGI9tj7Th9NFNzy2Vtb+Ekr+dz8bIIdasodf0oQA=";
+            };
+            subPackages = [
+              "cmd/devx"
+            ];
+            vendorHash = "sha256-nHSV6yH2lYUg1wKgq2i/CBz0MVYbldnZ/pN0s6QQ2t4=";
+
+            meta = with pkgs.lib; {
+              description = ''
+                A tool for generating, validating & sharing all your configurations,
+                powered by CUE. Works with Kubernetes, Terraform, Compose, GitHub actions and much more...
+              '';
+              homepage = "https://devx.stakpak.dev/";
+              license = licenses.asl20;
+              platforms = platforms.linux;
+            };
+            tags = [
+              "devx"
+              "cue"
+              "Kubernetes"
+            ];
+          };
+          docker = pkgs.dockerTools.buildImage {
+            name = "devx";
+            tag = version;
+            copyToRoot = pkgs.buildEnv {
+              name = "image-root";
+              paths = [ self.packages.${system}.default ];
+              pathsToLink = [ "/bin" ];
+            };
+            config = {
+              Cmd = [ "/bin/devx" ];
+            };
+          };
+        }
+      );
+
+      devShells = forAllSystems (
+        system:
+        let
+          pkgs = nixpkgsFor.${system};
+        in
+        {
+          default = pkgs.mkShell {
+            buildInputs = with pkgs; [
+              go
+              gopls
+              gotools
+              go-tools
+            ];
+          };
+        }
+      );
+    };
+}