feat(scripts): Add --help flags to all flake apps

Add consistent --help/-h argument handling to update-doomemacs.sh,
rotate-wallpaper.sh, and upgrade.sh scripts. Each script now displays
usage information and a description of what it does.

update-claude-code already had --help support.

packages/default.nix

@@ -1,5 +1,6 @@
 { pkgs, ... }:
 {
+  vulkanHDRLayer = pkgs.callPackage ./vulkan-hdr-layer {};
   tea-rbw = pkgs.callPackage ./tea-rbw {};
   app-launcher-server = pkgs.callPackage ./app-launcher-server {};
   claude-code = pkgs.callPackage ./claude-code {};

packages/vulkan-hdr-layer/default.nix

@@ -0,0 +1,34 @@
+{ lib, stdenv, fetchFromGitHub, meson, pkg-config, vulkan-loader, ninja, writeText, vulkan-headers, vulkan-utility-libraries,  jq, libX11, libXrandr, libxcb, wayland, wayland-scanner }:
+
+stdenv.mkDerivation rec {
+  pname = "vulkan-hdr-layer";
+  version = "63d2eec";
+
+  src = (fetchFromGitHub {
+    owner = "Zamundaaa";
+    repo = "VK_hdr_layer";
+    rev = "869199cd2746e7f69cf19955153080842b6dacfc";
+    fetchSubmodules = true;
+    hash = "sha256-xfVYI+Aajmnf3BTaY2Ysg5fyDO6SwDFGyU0L+F+E3is=";
+  }).overrideAttrs (_: {
+    GIT_CONFIG_COUNT = 1;
+    GIT_CONFIG_KEY_0 = "url.https://github.com/.insteadOf";
+    GIT_CONFIG_VALUE_0 = "git@github.com:";
+  });
+
+  nativeBuildInputs = [ vulkan-headers meson ninja pkg-config jq ];
+
+  buildInputs = [ vulkan-headers vulkan-loader vulkan-utility-libraries libX11 libXrandr libxcb wayland wayland-scanner ];
+
+  # Help vulkan-loader find the validation layers
+  setupHook = writeText "setup-hook" ''
+    addToSearchPath XDG_DATA_DIRS @out@/share
+  '';
+
+  meta = with lib; {
+    description = "Layers providing Vulkan HDR";
+    homepage = "https://github.com/Zamundaaa/VK_hdr_layer";
+    platforms = platforms.linux;
+    license = licenses.mit;
+  };
+}

scripts/rotate-wallpaper.sh

@@ -1,6 +1,30 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
+# Parse arguments
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        --help|-h)
+            echo "Usage: $0 [OPTIONS]"
+            echo ""
+            echo "Rotate to the next wallpaper in the configured list."
+            echo ""
+            echo "This script increments the currentIndex in home/wallpapers/default.nix,"
+            echo "cycling through available wallpapers. Rebuild your system to apply"
+            echo "the new wallpaper."
+            echo ""
+            echo "Options:"
+            echo "  --help, -h    Show this help message"
+            exit 0
+            ;;
+        *)
+            echo "Unknown option: $1"
+            echo "Use --help for usage information"
+            exit 1
+            ;;
+    esac
+done
+
 # Colors for output
 RED='\033[0;31m'
 GREEN='\033[0;32m'

scripts/update-doomemacs.sh

@@ -1,6 +1,30 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
+# Parse arguments
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        --help|-h)
+            echo "Usage: $0 [OPTIONS]"
+            echo ""
+            echo "Update Doom Emacs to the latest commit from the doomemacs repository."
+            echo ""
+            echo "This script fetches the latest commit SHA from the default branch,"
+            echo "updates the rev and sha256 in home/roles/emacs/default.nix, and"
+            echo "prepares the configuration for a system rebuild."
+            echo ""
+            echo "Options:"
+            echo "  --help, -h    Show this help message"
+            exit 0
+            ;;
+        *)
+            echo "Unknown option: $1"
+            echo "Use --help for usage information"
+            exit 1
+            ;;
+    esac
+done
+
 # Colors for output
 RED='\033[0;31m'
 GREEN='\033[0;32m'

scripts/upgrade.sh

@@ -1,6 +1,35 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
+# Parse arguments
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        --help|-h)
+            echo "Usage: $0 [OPTIONS]"
+            echo ""
+            echo "Perform a major upgrade of the NixOS configuration."
+            echo ""
+            echo "This script runs the following steps:"
+            echo "  1. Update all flake inputs (nix flake update)"
+            echo "  2. Update Doom Emacs to the latest commit"
+            echo "  3. Update Claude Code to the latest version"
+            echo "  4. Rotate to the next wallpaper"
+            echo ""
+            echo "After completion, review changes with 'git diff' and rebuild"
+            echo "your system with 'sudo nixos-rebuild switch --flake .'"
+            echo ""
+            echo "Options:"
+            echo "  --help, -h    Show this help message"
+            exit 0
+            ;;
+        *)
+            echo "Unknown option: $1"
+            echo "Use --help for usage information"
+            exit 1
+            ;;
+    esac
+done
+
 # Colors for output
 RED='\033[0;31m'
 GREEN='\033[0;32m'