feat: add omarchy theme template system with management scripts

- New default/themed/ templates (alacritty, btop, foot, ghostty, helix,
  hyprland, hyprlock, kitty, mako, obsidian, rofi, swayosd, tmux,
  walker, waybar, keyboard.rgb, gum.env, etc.)
- Add omarchy-* theme management scripts (install, refresh, set, remove,
  update, bg-set, colors-from-alacritty, current, etc.)
- Add omarchy restart/hook scripts (btop, hyprctl, hypridle, mako, tmux)
- Add installer/environment.sh for shared env vars
- Add 19 theme directories with colors.toml, vscode.json, backgrounds,
  and app-specific configs (catppuccin, everforest, gruvbox, nord,
  tokyo-night, rose-pine, etc.)
- Update bing-wallpaper script to use new .config/omarchy path

script/omarchy-hook

@@ -0,0 +1,28 @@
+#!/bin/bash
+
+# omarchy:summary=Run a named hook from ~/.config/omarchy/hooks/<name> and ~/.config/omarchy/hooks/<name>.d/.
+# omarchy:args=[name] [args...]
+
+set -e
+
+if (( $# < 1 )); then
+  echo "Usage: omarchy-hook [name] [args...]"
+  exit 1
+fi
+
+HOOK=$1
+HOOK_PATH="$HOME/.config/omarchy/hooks/$1"
+HOOK_DIR="$HOOK_PATH.d"
+shift
+
+if [[ -f $HOOK_PATH ]]; then
+  bash "$HOOK_PATH" "$@" || echo "Hook failed: $HOOK_PATH"
+fi
+
+if [[ -d $HOOK_DIR ]]; then
+  for hook in "$HOOK_DIR"/*; do
+    [[ -f $hook ]] || continue
+    [[ $hook == *.sample ]] && continue
+    bash "$hook" "$@" || echo "Hook failed: $hook"
+  done
+fi