feat: auto-update Claude Code from nixpkgs-unstable

- Add nixpkgs-unstable input for latest Claude Code versions
- Remove duplicate home-manager config from configuration.nix (handled by flake)
- Remove fetchTarball/fetchGit calls incompatible with pure flake mode
- Add shell function to auto-update unstable on nixos-rebuild

configuration.nix

@@ -2,27 +2,13 @@
 # your system.  Help is available in the configuration.nix(5) man page
 # and in the NixOS manual (accessible by running 'nixos-help').
 
-{ config, pkgs, ... }:
+{ config, pkgs, pkgs-unstable, ... }:
 
-let
-  # Fetch home-manager
-  home-manager = builtins.fetchTarball {
-    url = "https://github.com/nix-community/home-manager/archive/release-25.11.tar.gz";
-  };
-
-  # Fetch kickstart-nvim
-  kickstart-nvim = builtins.fetchGit {
-    url = "https://github.com/0xWheatyz/kickstart.nvim";
-    ref = "master";
-  };
-in
 {
-  imports =
-    [ # Include the results of the hardware scan.
-      ./hardware-configuration.nix
-      # Import home-manager module
-      (import "${home-manager}/nixos")
-    ];
+  imports = [
+    ./hardware-configuration.nix
+    # home-manager is imported via flake.nix
+  ];
 
  ## Commented out as defined at the end of the page
 
@@ -121,7 +107,7 @@ in
     code-cursor
     adwaita-icon-theme
     obsidian
-    claude-code
+    pkgs-unstable.claude-code  # Use unstable for latest version
   ];
 
   # Some programs need SUID wrappers, can be configured further or are
@@ -151,34 +137,7 @@ in
   # (e.g. man configuration.nix or on https://nixos.org/nixos/options.html).
   system.stateVersion = "25.11"; # Did you read the comment?
 
-  # Home Manager Configuration
-  home-manager.useGlobalPkgs = true;
-  home-manager.useUserPackages = true;
-  home-manager.users.l-wyatt = import ./home.nix;
-  home-manager.sharedModules = [
-    # Kickstart-nvim module
-    ({ config, lib, pkgs, ... }: {
-      options.programs.neovim-kickstart = {
-        enable = lib.mkEnableOption "kickstart.nvim configuration";
-      };
-
-      config = lib.mkIf config.programs.neovim-kickstart.enable {
-        home.file.".config/nvim" = {
-          source = kickstart-nvim;
-          recursive = true;
-        };
-
-        home.packages = with pkgs; [
-          neovim
-          ripgrep
-          fd
-          gcc
-          gnumake
-          git
-        ];
-      };
-    })
-  ];
+  # Home Manager Configuration is handled in flake.nix
 
   ### Start of self configuration
   # Configure grub to provide ubuntu option