Use virtio-gpu with viogpudo on Arm64 Windows 11

Replace ramfb with virtio-gpu-pci at 2048x1280 and install the viogpudo
driver from the VirtIO ISO. ramfb has a fixed mode, and keeping both
adapters left Windows with a second, fixed-mode monitor.

Windows Setup and the base image have no viogpudo driver, so on the
launch that creates the system disk the launcher also adds a ramfb ahead
of the config files. The display window shows the first GPU.

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

qemu/windows11-darwin-arm64.ini

@@ -24,11 +24,15 @@
   driver = "virtio-net-pci"
   netdev = "net0"
 
-# Unlike q35, "virt" has no default GPU or keyboard. ramfb is used rather than
-# virtio-gpu because the firmware's virtio-gpu output freezes at the Windows
-# boot manager; Windows drives either one through its basic display driver.
+# Unlike q35, "virt" has no default GPU or keyboard. virtio-gpu is the only
+# display, driven by viogpudo (installed by Configure-Windows.ps1). ramfb is not
+# added because Windows would then see a second adapter with a fixed-mode
+# monitor. xres/yres set the preferred mode in the EDID (QEMU defaults to
+# 1280x800); viogpudo accepted 1920x1200 and 2048x1280 but not 2560x1600.
 [device "gpu0"]
-  driver = "ramfb"
+  driver = "virtio-gpu-pci"
+  xres = "2048"
+  yres = "1280"
 
 [device "kbd0"]
   driver = "usb-kbd"