Popular is a top 10; a Directory lists every listed feed A to Z

- GET /api/popular returns the ten most subscribed feeds. The new GET
  /api/directory returns every feed that may be listed, sorted by name,
  from the same list: everyone counted, you included, never a URL, never
  a private feed or a feed inside an OPML. POST /api/popular/{id} still
  subscribes to anything on it.
- A Directory button sits beside Popular; both open the same list
  screen. The sidebar toolbar wraps rather than squeezing four buttons.
- Tests: the directory is A to Z, Popular is its top ten, Paid Show is
  in neither, and subscribing works from the directory.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016HdTEWQNrzyFULijigkmMn

docs/users.md

@@ -70,8 +70,9 @@ list with their own read state. Unsubscribing removes it from their list alone;
 subscriber leaves does the feed stop being scanned, and even then its files and history stay, so
 re-subscribing does not pull the back catalogue again.
 
-**Popular**, at the top of the feed list and in the Add feed dialog, lists what everyone on this
-server subscribes to, you included, most subscribers first. Your own feeds are marked Subscribed.
+**Popular**, at the top of the feed list and in the Add feed dialog, lists the ten feeds with the
+most subscribers on this server, you included. **Directory**, beside it, lists every one of them
+A to Z. Your own feeds are marked Subscribed.
 It shows a title, artwork and a count, never a URL or who reads it. Feeds from an
 OPML subscription are left out, since they come with the OPML. So is anything that looks private: a
 login configured for the feed, credentials in its URL, or a key such as `auth=` or `token=` in the