Roles:
- JakeBreathild is now staff + superuser (the real account); the 'jake'
smoke-test account was demoted to a regular user
- /me exposes is_superuser and the account page shows an admin badge
e621 metadata:
- MediaItem gains e621_post_id and e621_data (trimmed post payload:
tags by category, rating, score, favourites, comments, sources,
description, pools, relationships, file info, uploader)
- Download to Library accepts the post payload from the SPA and stores
it; the item's custom rating is seeded from the e621 rating when empty
- Library detail shows an e621 metadata card: link to the in-app post,
score/favourites/comments, taxonomy-coloured tags, DText description,
sources and pools; grid cards get an e621 badge and fall back to the
e621 rating for their colour (display_rating)
- Guest visibility now also considers e621 tags, so downloaded explicit
content is hidden from anonymous visitors