Enhance GTK theme configuration and taskbar setup in cloud-init scripts</message>

<message>Update the cloud-init scripts to improve GTK theme settings by enforcing dark mode through gsettings and preserving the icon theme for a cohesive user experience. Additionally, enhance the first-boot script to install a Chromium kiosk launcher icon on the desktop and in the application menu, along with a five-tap close functionality for Chromium. These changes streamline the user interface and ensure a consistent dark theme across applications and the taskbar.

emmc-provisioning/cloud-init/config-files/gtk.css

@@ -0,0 +1,49 @@
+/* User GTK3 override: force start menu and all menus/popovers to full dark.
+ * Colors match Adwaita-dark (menu/popover #2d2d2d, text #e0e0e0).
+ * Placed in ~/.config/gtk-3.0/gtk.css.
+ */
+
+/* Adwaita-dark menu/popover background */
+menu,
+.menu,
+menubar,
+.menubar,
+popover,
+.popover,
+popover.menu {
+  background-color: #2d2d2d !important;
+  background: #2d2d2d !important;
+  color: #e0e0e0 !important;
+}
+
+/* Inner content (often the cause of light background) */
+menu contents,
+.menu contents,
+popover contents,
+popover list,
+popover flowbox,
+popover box {
+  background-color: #2d2d2d !important;
+  background: #2d2d2d !important;
+  color: #e0e0e0 !important;
+}
+
+menu menuitem,
+.menu menuitem,
+menubar menuitem,
+popover modelbutton,
+popover menuitem {
+  background-color: transparent !important;
+  background: transparent !important;
+  color: #e0e0e0 !important;
+}
+
+menu menuitem:hover,
+.menu menuitem:hover,
+menubar menuitem:hover,
+popover modelbutton:hover,
+popover menuitem:hover {
+  background-color: rgba(255, 255, 255, 0.1) !important;
+  background: rgba(255, 255, 255, 0.1) !important;
+  color: #ffffff !important;
+}