docs: correct sendPendingCtrlL comment (it has no callers)

The prior wording claimed the no-op stub was kept so SSE idle/working
handlers could call it without guards, but there are no callers anywhere.
Reword to reflect that it's a vestigial, intentionally-retained guard
documenting why Ctrl+L must not be auto-sent. Comment-only; minified
build output is unchanged.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/web/public/terminal-ui.js

@@ -1731,8 +1731,8 @@ Object.assign(CodemanApp.prototype, {
     }
   },
 
-  // Legacy hook for newly-created sessions; kept as a no-op so the SSE
-  // idle/working handlers can still call it without conditional guards.
+  // Vestigial no-op: this method has no callers today. It's kept (not deleted)
+  // as a documented guard so the Ctrl+L behavior below isn't reintroduced.
   //
   // Originally this sent Ctrl+L (\x0c) when a flagged session first reached
   // idle/working to scrub mux-init junk from the screen. Two problems: