android: the room list filtered by name, the rest on demand

Soulseek lists hundreds of rooms; the phone showed the first 80 and no way
to the rest. Community → Rooms now has a filter by name and extends the
list 200 at a time.

ANDROID.md

@@ -172,6 +172,9 @@ namesake), the catalog's released records minus the shelf's by loose title,
 dimmed cards that open the catalog record page, the totals remembered in
 `library.gaps.v1` so the line says its number before the lookup.
 
+The server's room list on Community is filtered by name and shows 80 at a
+time with a way to the rest (Soulseek lists hundreds).
+
 ## A peer, and their shares
 
 A raw result's ⋯ (or a long press on its head) is the peer's sheet: play