[Request] option to set chat background as JPEG/GIF (with animation support)

[leonessawebb-rgb]

Problem
The Themes system currently lets you restyle colors/fonts, but there's no built-in
way to set a custom image as the chat background.

Proposed solution
Add a background image option under Settings > Themes:
Upload a JPEG/PNG for a static background, or a GIF for an animated one.
If a GIF is uploaded, keep it animated (not frozen to the first frame)
-Optional: opacity/blur slider so the background doesn't hurt message readability.
--Quality-of-life addition to an already flexible Themes system.

[SirThinksAl0t]

+1