feat(tui): scroll long names in every list and page through popups and chat

The sideways keys the results had (h/l, arrows, 0 and $) now scroll a
transfer's file name and a query too, each list on its own. The browse tree
and the room list take Home/End, PgUp/PgDn and the vim jumps like the main
lists, and a chat log, room or private, pages back through its history and
holds its place while new messages arrive; what arrives meanwhile counts as
unread until the reader returns to the end.

README.md

@@ -98,7 +98,9 @@ Searches, Downloads and Info share the row underneath. `Tab`/`Shift-Tab` or
 `1`–`3` move the focus between panes, `z` zooms the focused pane to the whole
 window, and `w` hides it so the others widen (its number brings it back).
 Every list takes `↑`/`↓`, `Home`/`End`, `PgUp`/`PgDn` and the vim keys, and
-`?` shows every key for where you are.
+`h`/`l` or `←`/`→` scroll a long file name or query sideways, `0` and `$` to
+either end. `PgUp`/`PgDn` scroll a chat log back through its history, and `?`
+shows every key for where you are.
 
 ### Daemon mode