Images stretched with sixel protocol

[xstasi]

When reproducing presentations using sixel, images are rendered stretched / with broken aspect ratio.

Steps to reproduce:

• Create a landscape picture
  • convert -size 1400x1080 xc:white white.png
• Create a presentation that displays it
  • echo '![](white.png)' > x.md
• Run the presentation using sixel
  • presenterm --image-protocol sixel x.md
  • The picture has a portrait ratio
• Run the presentation again using ascii
  • presenterm --image-protocol ascii-blocks x.md
  • The picture has the correct ratio

Explicitly setting width doesn't help either.

Thanks!

EDIT: Apparently this only happens when running in foot for some reason, in konsole the pictures are displayed correctly. But konsole causes the ghosting problem of #379 🫠