C14.13: a shorter comment

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

apps/ely-mark/src/places.rs

@@ -108,7 +108,7 @@ impl Desk {
         }
     }
 
-    /// Line and column `at` in a tab, or a file once open.
+    /// Line and column `at` in a tab or file.
     pub fn open_at(
         &mut self,
         tab: Option<u64>,