Download a page scan as a zip

One zip with the optimized copy of every image of the scan that has finished, in the order the scanner found them. Images still compressing are left out, so wait for images_in_progress to reach 0 first.

The zip is laid out like the page: each image sits in the folders of its address (wp-content/uploads/hero.jpg), and an image from another host under a folder named after that host. It keeps its file name while its format is unchanged; a converted one takes its new extension. manifest.csv at the root lists every image address the scan fetched with its file in the zip, status, formats and sizes, then the addresses it passed over (a duplicate names the file it shares) and how many images your plan's per-scan limit left out.