Guest environment for DF-5591 verification (2026-10-08)

uname -a:
DragonFly dfbsd 6.5-DEVELOPMENT DragonFly 6.5-DEVELOPMENT #0: Thu Jul  2 06:02:54 UTC 2026     root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC  x86_64

Kernel: X86_64_GENERIC; `device vga0 at isa?` (sys/config/X86_64_GENERIC:155);
vga compiled in (kernel, not KLD — kldstat shows kernel + ehci/xhci only).

Live: vga0 attached on isa1 (windows 0x3c0-0x3df / 0xa0000-0xbffff),
vgapci0+drm0 on pci0 (Bochs VGA hybrid). No /dev/vga0 (GENERIC lacks
FB_INSTALL_CDEV). Guest left clean (read-only queries only).