add flake.nix

flake.nix

@@ -0,0 +1,62 @@
+{
+  description = "headless browser designed for AI and automation";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/release-24.11";
+
+    iguana.url = "github:mookums/iguana";
+    iguana.inputs.nixpkgs.follows = "nixpkgs";
+
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs =
+    {
+      nixpkgs,
+      iguana,
+      flake-utils,
+      ...
+    }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        zigVersion = "0_14_0";
+        iguanaLib = iguana.lib.${system};
+
+        pkgs = import nixpkgs {
+          inherit system;
+          overlays = [
+            (iguanaLib.mkZigOverlay zigVersion)
+            (iguanaLib.mkZlsOverlay zigVersion)
+          ];
+        };
+
+        # This build pipeline is very unhappy without an FHS-compliant env.
+        fhs = pkgs.buildFHSUserEnv {
+          name = "fhs-shell";
+          targetPkgs =
+            pkgs: with pkgs; [
+              zig
+              zls
+              pkg-config
+              cmake
+              gperf
+              expat.dev
+              python3
+              glib.dev
+              glibc.dev
+              zlib
+              ninja
+              gn
+              gcc-unwrapped
+              binutils
+              clang
+              clang-tools
+            ];
+        };
+      in
+      {
+        devShells.default = fhs.env;
+      }
+    );
+}