Panel icons, trident menu button, Ctrl+Q in dbanner (0.9.4)

- Light theme: panel icons and labels are dark instead of pale grey.
- das-trident icon and das-panel-icon star|trident for the menu button.
- dbanner quits with Ctrl+Q like dprompt ("q" stays on the start screen).
- das-shell 0.4.0, das-theme 0.2.0, das-settings 0.5.0.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

srcpkgs/das-settings/files/bin/das-panel-icon

@@ -0,0 +1,22 @@
+#!/bin/bash
+# Picks the icon of the menu button on the panel: das-panel-icon star|trident|<icon name>.
+set -u
+
+case ${1:-} in
+star) icon=das-logo ;;
+trident) icon=das-trident ;;
+"")
+  echo "usage: das-panel-icon star|trident|ICON-NAME" >&2
+  echo "now: $(xfconf-query -c xfce4-panel -p /plugins/plugin-1/button-icon 2>/dev/null || echo das-logo)" >&2
+  exit 1
+  ;;
+*) icon=$1 ;;
+esac
+
+prop=/plugins/plugin-1/button-icon
+xfconf-query -c xfce4-panel -p "$prop" -s "$icon" 2>/dev/null ||
+  xfconf-query -c xfce4-panel -p "$prop" -n -t string -s "$icon" || exit 1
+# whiskermenu keeps its own copy in the rc file, which wins over xfconf
+rc="${XDG_CONFIG_HOME:-$HOME/.config}/xfce4/panel/whiskermenu-1.rc"
+[[ -f $rc ]] && sed -i "s|^button-icon=.*|button-icon=$icon|" "$rc"
+xfce4-panel -r >/dev/null 2>&1 &