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/architecture.md

@@ -110,7 +110,7 @@ else a `401`.
 | `POST /api/enclosures/{id}/download`, `DELETE /api/enclosures/{id}` | `?force=true` overrides the shared-file warning |
 | `POST /api/fetch` | |
 | `GET /api/opml`, `POST /api/opml` | export your subscriptions; subscribe to every feed in an OPML |
-| `GET /api/popular`, `POST /api/popular/{id}` | what everyone here subscribes to, you included (id, title, art, count, whether it is yours; never a URL, never a private feed); subscribe by id |
+| `GET /api/popular`, `GET /api/directory`, `POST /api/popular/{id}` | the ten most subscribed feeds, and every listable feed A to Z, with everyone counted (id, title, art, count, whether it is yours; never a URL, never a private feed); subscribe by id |
 | `GET /api/settings`, `PATCH /api/settings` | admin-only to write |
 | `GET /api/users`, `POST /api/users`, `PATCH /api/users/{id}`, `DELETE /api/users/{id}` | admin-only; the only admin cannot be demoted or removed |
 | `GET /api/events` | SSE, the same broadcast the socket carries |