Replace customPkgs with pkgs.custom and add pkgs.unstable and flake update

flake.nix

@@ -3,6 +3,7 @@
 
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs/nixos-25.05";
+    nixpkgs-unstable.url = "github:nixos/nixpkgs/nixos-unstable";
     nixos-wsl.url = "github:nix-community/NixOS-WSL/main";
     
     nix-darwin = {
@@ -27,12 +28,21 @@
     };
   };
 
-  outputs = { self, nixpkgs, nixos-wsl, ... } @ inputs: let
+  outputs = { self, nixpkgs, nixpkgs-unstable, nixos-wsl, ... } @ inputs: let
     nixosModules = [
       ./roles
     ] ++ [
       inputs.home-manager.nixosModules.home-manager
       {
+        nixpkgs.overlays = [
+          (final: prev: {
+            unstable = import nixpkgs-unstable {
+              system = prev.system;
+              config.allowUnfree = true;
+            };
+            custom = prev.callPackage ./packages {};
+          })
+        ];
         home-manager.useGlobalPkgs = true;
         home-manager.useUserPackages = true;
         home-manager.sharedModules = [
@@ -48,6 +58,15 @@
     ] ++ [
       inputs.home-manager.darwinModules.home-manager
       {
+        nixpkgs.overlays = [
+          (final: prev: {
+            unstable = import nixpkgs-unstable {
+              system = prev.system;
+              config.allowUnfree = true;
+            };
+            custom = prev.callPackage ./packages {};
+          })
+        ];
         home-manager.useGlobalPkgs = true;
         home-manager.useUserPackages = true;
         home-manager.extraSpecialArgs = {