ac-native: dump full DRM diagnostics on display failure
When no display is found, dump /dev/dri contents, PCI GPU devices,
and dmesg DRM/i915 lines to both console (30s visible) and USB log.
This will tell us exactly why the Yoga 11e GPU isn't probing.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>