docs(user): two more code-grounding fixes from the verification sweep

- sync-guide matching ladder was missing rung 8: Title only at 0.3
  confidence, last-resort after title+author+size (book_matching.go
  priorities 1-8, file-path priority handled at the API layer).
- library-browsing said the sort dropdown had 'more' options than it
  does: exactly five (Title A-Z/Z-A, Author A-Z, Date Added, Page
  Count).

Sweep results, all verified against source: themes.md 24+13=37 exact
(web/src/theme.ts union), reader-guide claims (corner zones, selection
copy, comics annotations disabled - bookmarks only) present in
web/src/reader/reader.ts, android-app.md strings (local-network
permission, login error table) in bookhoard-app source, calibre
dc:title/calibre:series parsing in media_scanner_calibre fixtures.

docs/user/library-browsing.md

@@ -6,8 +6,8 @@ current library, as a wall of covers. From there you narrow, sort, and open.
 ## The All Books toolbar
 
 - The **search box** finds titles, authors, and more as you type
-- The **Sort** dropdown orders the wall (title, author, date added, page
-  count, and more)
+- The **Sort** dropdown orders the wall: **Title (A-Z)**, **Title (Z-A)**,
+  **Author (A-Z)**, **Date Added**, or **Page Count**
 - The **Filters** button opens the filter drawer — authors, tags, series,
   progress, and every other field (the full how-to lives in
   [Filters — the complete guide](filters/index.md); this page sticks to