Rail and drawer: only the 5 tags most recently used or viewed (#5931)

A long tag list pushed the drawer's Archive, Trash and Sync off screen on
Android, where Tags still sat above them (#5915 only reordered the web rail).
Tags now come last on Android too, and both clients list the five tags most
recently used or viewed, by name, with "All tags (N)" opening the rest in
place.

Used: the newest untrashed note carrying the tag. GET /api/labels and the
core's list_labels return it as last_used, and each client also folds in the
notes it holds, so a tag applied a moment ago counts before the next listing.
Viewed: opening the tag's lens, remembered on the device (per user on the web).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

android/app/src/main/res/values/strings.xml

@@ -133,6 +133,8 @@
     <!-- Tag management. The whole vocabulary is "tag" (see Scribe #2966); the
          schema still says Label, and no string here needs to know that. -->
     <string name="tags_manage">Manage tags</string>
+    <string name="tags_show_all">All tags (%1$d)</string>
+    <string name="tags_show_fewer">Fewer tags</string>
     <string name="tags_title">Tags</string>
     <string name="tags_back">Back</string>
     <string name="tags_new_hint">New tag</string>