[Feature] Easy category scraping

[brandonsturgeon]

In other scrapers, they use a fancy /page/preview endpoint that lets them generate lists of all the pages in the category they want.

• ref
• ref

It would be nice if we could support this 1-1, though I worry because the category thing appears to be an internal property that isn't exposed on the frontend.

We can potentially query these ourselves during buildtime and store them - same thing with the tags.

Then, we just store the resulting .json in public/ or upload to R2