Add Theme Menu Switcher (#154)

* Add theme menu for quick theme switching

* Bind theme menu

* Fix current theme being selected

* Replace omarchy-theme-next binding with theme menu

* Add omarchy-theme-set and refactor theme menu script

* Add solid black fallback if background image does not exist in current theme

bin/omarchy-theme-set

@@ -0,0 +1,47 @@
+#!/bin/bash
+
+# omarchy-theme-set: Set a theme, specified by its name.
+# Usage: omarchy-theme-set <theme-name>
+
+THEMES_DIR="$HOME/.config/omarchy/themes/"
+CURRENT_THEME_DIR="$HOME/.config/omarchy/current/theme"
+
+if [[ -z "$1" ]]; then
+  echo "Usage: omarchy-theme-set <theme-name>" >&2
+  exit 1
+fi
+
+THEME_NAME="$1"
+THEME_PATH="$THEMES_DIR/$THEME_NAME"
+BACKGROUND_PATH="$HOME/.config/omarchy/backgrounds/$THEME_NAME"
+
+# Check if the theme entered exists
+if [[ ! -d "$THEME_PATH" ]]; then
+  echo "Theme '$THEME_NAME' does not exist in $THEMES_DIR" >&2
+  exit 2
+fi
+
+# Update theme symlinks
+ln -nsf "$BACKGROUND_PATH" "$HOME/.config/omarchy/current/backgrounds"
+ln -nsf "$THEME_PATH" "$CURRENT_THEME_DIR"
+
+# Trigger alacritty config reload
+touch "$HOME/.config/alacritty/alacritty.toml"
+
+# Restart components to apply new theme
+pkill -SIGUSR2 waybar
+makoctl reload
+hyprctl reload
+
+# Set new background
+first_bg=$(find "$HOME/.config/omarchy/current/backgrounds/" -type f | head -n 1)
+if [[ -n "$first_bg" ]]; then
+  ln -nsf "$first_bg" "$HOME/.config/omarchy/current/background"
+  pkill -x swaybg
+  setsid swaybg -i "$HOME/.config/omarchy/current/background" -m fill &
+else
+  # Background does not exist for this theme - fallback to solid black.
+  rm -f "$HOME/.config/omarchy/current/background"
+  pkill -x swaybg
+  setsid swaybg -c '#000000' &
+fi