Fixing dynamic resolution switching in docker-steam-headless

I recently fixed dynamic resolution switching for docker-steam-headless with Sunshine + Moonlight and packaged it into a small reusable overlay.

The issue was that X11 framebuffer size and XRandR output mode could desync when switching between different aspect ratios, which caused black borders and weird scaling depending on the Moonlight client.

I also wrote a blog post explaining the whole debugging process, the XRandR quirks, why some approaches failed, and how the final solution works:

https://blog.dera.page/posts/fixing-dynamic-resolution-switching-in-docker-steam-headless/

Repo:
https://github.com/DimitriTimoz/steam-headless-adaptive-resolution