Changes MapPixelFormatToGuestTextureFormat to default to format 56 (8-bit
RGBA) when the game uses a pixel format not yet in the known list, with a
stderr warning that reports the exact format value for project issue reports.
Previously, unknown formats returned 0, which caused RegisterKnownDisplayBuffer
to skip registration entirely. The GPU backend then couldn't find the buffer
during flip, producing vk.flip_capture_failed, and some games later hit a
Debug.Assert in ExecuteOrderedGuestFlipWait.
The fallback produces wrong colors for the affected games but lets them render
and display output, which is strictly better than a black screen or access
violation crash. The pixel format is printed to stderr so developers can
identify it and add proper support.
Co-authored-by: meowman <haadii2005@gamil.com>
faf3a397a8