Backend (new apps.follows):
- FollowedTag/FollowedPool/FollowedPost models; per-user follows with
unseen tracking, plus FollowCloud for the cached blacklist cloud.
- Two periodic commands sharing one fetch path: sync_followed_tags and
sync_followed_pools fetch each followed tag/pool's newest posts (one
e621 search per unique follow), store unseen feed rows, refresh covers
and pool metadata; both fall back to anonymous e621 access.
- API: /api/follows/tags|pools (follow, unfollow, mark seen), a merged
feed with per-follow filtering, and /api/follows/cloud/ which rebuilds
the blacklisted-tag cloud in a daemon thread when its 10 min cache is
stale (polling returns building/ready).
- e621 client now supports anonymous reads; trimmed posts carry preview
URLs for covers and feed tiles.
Frontend:
- /followed page: follow forms, cover cards with unseen badges and
Mark seen, merged feed with filter/unseen toggle, and a blacklist
cloud panel that polls while building. Followed nav entry added.
