added flake for reproducible builds on NixOS

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1772433332,
+        "narHash": "sha256-izhTDFKsg6KeVBxJS9EblGeQ8y+O8eCa6RcW874vxEc=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "cf59864ef8aa2e178cccedbe2c178185b0365705",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,44 @@
+{
+  description = "4jcraft-nix dev shell";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
+  };
+
+  outputs = { nixpkgs, ... }:
+  let
+    allSystems = [
+      "x86_64-linux"
+      "aarch64-linux"
+      "x86_64-darwin"
+      "aarch64-darwin"
+    ];
+
+    forAllSystems = f: nixpkgs.lib.genAttrs allSystems (system: f {
+      pkgs = import nixpkgs { inherit system; };
+    });
+  in
+  {
+    devShells = forAllSystems ({ pkgs }:
+      let
+      libs = with pkgs; [
+        openssl.dev
+        libGL
+        glfw
+      ];
+      packages = with pkgs; [
+        gcc
+        cmake
+        gnumake
+      ];
+      in
+      {
+        default = pkgs.mkShell {
+          LD_LIBRARY_PATH = "/run/opengl-driver/lib";
+          buildInputs = libs;
+          nativeBuildInputs = packages;
+        };
+      }
+    );
+  };
+}