Replace bar-settings with unified settings plugin

Consolidates bar-settings into a single 'settings' plugin with sidebar
categories: Defaults, Style, Bar, System, Plugins. Updates supporting
commands (omarchy-launch-settings, omarchy-style-corners-quickshell,
omarchy-theme-list-with-previews, omarchy-hyprland-monitor-scaling-set)
and refreshes sidebar glyphs to Nerd Font icons.

bin/omarchy-style-corners

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-# omarchy:summary=Set Hyprland, Hyprlock, Mako, and Walker corners to sharp or round
+# omarchy:summary=Set Hyprland, Hyprlock, Mako, Walker, and Quickshell corners to sharp or round
 # omarchy:args=<sharp|round>
 # omarchy:examples=omarchy style corners round | omarchy style corners sharp
 
@@ -13,6 +13,7 @@ omarchy-style-corners-hyprland "$1"
 omarchy-style-corners-hyprlock "$1"
 omarchy-style-corners-mako "$1"
 omarchy-style-corners-walker "$1"
+omarchy-style-corners-quickshell "$1"
 
 case $1 in
   sharp) omarchy-notification-send "Sharp corners enabled" -g 󰝣 ;;