feat: add openshell package

pkgs/openshell/default.nix

@@ -0,0 +1,35 @@
+{
+  lib,
+  stdenv,
+  fetchurl,
+}: let
+  sources = lib.importJSON ./sources.json;
+  source = sources.sources.${stdenv.hostPlatform.system};
+in
+  stdenv.mkDerivation {
+    pname = "openshell";
+    version = lib.removePrefix "v" sources.version;
+
+    src = fetchurl {
+      inherit (source) url hash;
+    };
+
+    unpackPhase = ''
+      tar -xzf $src
+    '';
+
+    installPhase = ''
+      install -Dm755 openshell $out/bin/openshell
+    '';
+
+    passthru.updateScript = ./update.sh;
+
+    meta = with lib; {
+      description = "Safe, private runtime for autonomous AI agents";
+      homepage = "https://github.com/NVIDIA/OpenShell";
+      license = licenses.asl20;
+      platforms = attrNames sources.sources;
+      mainProgram = "openshell";
+      maintainers = [];
+    };
+  }