add nix build files

flake.nix

@@ -0,0 +1,61 @@
+# flake.nix
+{
+  description = "kte – a small terminal text editor";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+      in
+        {
+          packages.default = pkgs.stdenv.mkDerivation {
+            pname = "kte";
+            version = "0.1.0";  # change if you have a version
+
+            src = ./.;
+
+            nativeBuildInputs = [ pkgs.cmake ];
+            buildInputs = with pkgs; [
+              ncurses   # provides libncursesw.so + headers via .dev output
+            ];
+
+            # Crucial: tell CMake to use wide ncurses and prefer pkg-config
+            cmakeFlags = [
+              "-DCURSES_NEED_NCURSES=TRUE"
+              "-DCURSES_NEED_WIDE=TRUE"
+              "-DUSE_PKGCONFIG=ON"
+            ];
+
+            # Optional: make it obvious in the build log
+            preConfigure = ''
+            echo "Using ncurses from ${pkgs.ncurses}"
+            echo "lib dir: ${pkgs.ncurses}/lib"
+            echo "include dir: ${pkgs.ncurses.dev}/include"
+          '';
+
+            meta = with pkgs.lib; {
+              description = "A small terminal text editor";
+              license = licenses.mit;  # change if needed
+              platforms = platforms.linux;
+              mainProgram = "kte";
+            };
+          };
+
+          devShells.default = pkgs.mkShell {
+            buildInputs = with pkgs; [
+              cmake
+              gdb
+              clang-tools  # for clangd, clang-format, etc.
+              ncurses
+            ];
+
+            # Makes ncurses visible to every tool (including manual cmake runs)
+            hardeningDisable = [ "all" ];  # optional, only if you hit fortify issues
+          };
+        });
+}