v0.2.4

Added

• Positions in human terms. A reading position can now carry the chapter
  name and a page-of-pages alongside the locator, so a resume card can say
  "Chapter 7 · page 142 of 312" instead of a bare percentage. /state reports
  these too, with the book's title and series, so a home screen can build a
  "reading now" card from one call.
• Book outline on demand. GET /api/ebooks/issue/:id/details now includes
  the book's estimated page count and its chapters with the page each starts
  on, derived from the file the first time it is asked for and cached.
• Highlights. A bookmark can carry a colour and the passage it marks —
  the shape the mobile readers use for highlights and notes. Older clients
  that only know bookmarks are unaffected.