review: the two-facts claim was stated in four places, and I changed one

Self-review against the code-review skill, and it is gotcha 48's own third
lesson turning up in the change that cites it: "when a fact is stated in
more than one place, changing it is a grep, not an edit."

`context/code/clients.md` said `#status` composes two facts in three further
places -- the shell.js inventory, the transports section and the two-numbers
section -- all still describing the `.` join this branch deletes. A reader
arriving at any of them would have been told the opposite of what the code
does. The minibuffer section also predated `#bottom-dock` and said nothing
about what happens when a toast and the prompt coincide.

Also drops `createToasts().showing()`, which nothing calls. It was
speculative API on a single-use object (CLAUDE.md section 2), and an
unexercised accessor on a timer is one more thing that can be wrong.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FC2jVn8Au7E9JPkw6bwXXH

web/shell.js

@@ -46,7 +46,6 @@ export function createToasts({
         onHide();
       }, ttlMs);
     },
-    showing: () => timer !== null,
   };
 }