Update Easter eggs

[blazoncek]

I know they may be controversial but Easter backgrounds (and other eggs) will need updating for 2026 and 2027 (and beyond). They have not been updated since 2024.

Or remove them entirely (all Easter eggs). Whichever makes more sense.

[DedeHai]

Most users enjoy and appreciate the changing background (with the occasional exception of course).
@Aircoookie will you provide new files?

[blazoncek]

Everything is in source files. Backgrounds are external, links in index.js.