custom wallpapers lol

let people add custom wallpapers to their Calendar page, since we r going full customization. Then when they export it, it won;t just be a white backround! Concept art at 4 in the morning 

<img width="1440" height="900" alt="Image" src="https://github.com/user-attachments/assets/0595e190-35c4-4173-8e15-c82a08ec26c9" />


- derexXD (Derek Chen)