Reading orders and spoiler-safe reading profiles

Reading order tracking - follow a series or universe reading order and track your position. The reading order page highlights books you've passed with a green background, and provides back/forward controls.

Reading profile dashboard - the reading profile page now has tabs separating spoiler controls from your book list, with rich cards showing progress, current/next book links, and inline controls.

Series reading orders - curators can create multiple named reading orders per series (e.g. "Publication Order", "Chronological Order") with drag-to-reorder management. A public widget shows the default order on series pages.

Rich descriptions - entity descriptions now support cross-references to other entities using inline links.