chore: modernize Astro Nix development shell

flake.nix

@@ -1,29 +1,35 @@
 {
-  description = "A Nix-flake-based Node.js development environment";
+  description = "Arizona Institute for Autism Astro development environment";
 
-  inputs.nixpkgs.url = "https://flakehub.com/f/NixOS/nixpkgs/0.1.*.tar.gz";
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
 
-  outputs = { self, nixpkgs }:
+  outputs =
+    { nixpkgs, ... }:
     let
-      supportedSystems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
-      forEachSupportedSystem = f: nixpkgs.lib.genAttrs supportedSystems (system: f {
-        pkgs = import nixpkgs { inherit system; overlays = [ self.overlays.default ]; };
-      });
+      supportedSystems = [
+        "x86_64-linux"
+        "aarch64-linux"
+        "aarch64-darwin"
+      ];
+
+      forAllSystems =
+        function: nixpkgs.lib.genAttrs supportedSystems (system: function nixpkgs.legacyPackages.${system});
     in
     {
-      overlays.default = final: prev: rec {
-        nodejs = prev.nodejs_22;
-        yarn = (prev.yarn.override { inherit nodejs; });
-      };
-
-      devShells = forEachSupportedSystem ({ pkgs }: {
+      devShells = forAllSystems (pkgs: {
         default = pkgs.mkShell {
           packages = with pkgs; [
-            node2nix nodejs nodePackages.pnpm yarn
-            python3
+            nodejs_24
+            git
+            curl
+            jq
+            ripgrep
             fd
+            python3
           ];
         };
       });
+
+      formatter = forAllSystems (pkgs: pkgs.nixfmt);
     };
 }