docs: refresh bootstrap examples and README

vars_baremetal_example.yml

@@ -61,11 +61,15 @@ system:
       sudo: true
     chroot:
       tool: "arch-chroot"
-    # firmware/microcode default to "auto" — on for physical, off for virtual.
+    desktop:
+      enabled: false
+      environment: ""    # gnome|kde|sway|hyprland (sway/hyprland are Archlinux only)
+      autologin: false   # false | a username from system.users (not bool true)
+    # firmware/microcode default to "auto" - on for physical, off for virtual.
     # gpu and peripherals.* default to "auto" tied to desktop.enabled.
     # Override only when you want non-default behavior.
     gpu:
-      enabled: false      # set true for desktop installs
+      enabled: "auto"        # auto = follows desktop.enabled; set true to force
       nvidia_driver: "auto"  # auto = open|proprietary|nouveau by GPU generation
     peripherals:
       displaylink: false  # explicit opt-in for DisplayLink docks