feat(desktop): switch to LightDM for X startup (matches Ubuntu LiveCD)

startx from user shell has /dev/fb0 permission issues and is fragile.
LightDM starts Xorg as root — standard LiveCD approach that works
on server hardware / IPMI KVM with nomodeset + fbdev/vesa.

- Add lightdm package, configure autologin as bee/openbox session
- Add /usr/share/xsessions/openbox.desktop
- Remove startx from .profile (LightDM manages X lifecycle)
- Remove Xwrapper.config needs_root_rights workaround (no longer needed)
- Enable lightdm.service in setup hook

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

iso/builder/config/hooks/normal/9000-bee-setup.hook.chroot

@@ -29,6 +29,7 @@ systemctl enable bee-audit.service
 systemctl enable bee-web.service
 systemctl enable bee-sshsetup.service
 systemctl enable ssh.service
+systemctl enable lightdm.service 2>/dev/null || true
 systemctl enable qemu-guest-agent.service 2>/dev/null || true
 systemctl enable serial-getty@ttyS0.service 2>/dev/null || true
 systemctl enable serial-getty@ttyS1.service 2>/dev/null || true

iso/builder/config/package-lists/bee.list.chroot

@@ -52,11 +52,11 @@ qrencode
 openbox
 tint2
 xorg
-xinit
 xterm
 chromium
 xserver-xorg-video-fbdev
 xserver-xorg-video-vesa
+lightdm
 
 # Firmware
 firmware-linux-free

iso/overlay/etc/lightdm/lightdm.conf.d/50-bee-autologin.conf

@@ -0,0 +1,5 @@
+[Seat:*]
+autologin-user=bee
+autologin-user-timeout=0
+autologin-session=openbox
+user-session=openbox

iso/overlay/home/bee/.profile

@@ -1,10 +1 @@
 export PATH="/usr/local/bin:$PATH"
-
-# On tty1 (IPMI KVM console): start X desktop directly on VT1
-# so the KVM shows the graphical UI without switching VTs.
-if [ "$(tty 2>/dev/null)" = "/dev/tty1" ] \
-    && [ -z "${DISPLAY:-}" ]; then
-    startx /usr/local/bin/bee-openbox-session -- :0 vt1 -nolisten tcp
-    echo ""
-    echo "X session ended. Type 'startx' to retry or use the shell."
-fi

iso/overlay/usr/share/xsessions/openbox.desktop

@@ -0,0 +1,6 @@
+[Desktop Entry]
+Name=Openbox
+Comment=Bee Hardware Audit Desktop
+Exec=/usr/local/bin/bee-openbox-session
+TryExec=openbox
+Type=Application