agent: Fix bug where wrong crease for @mention would be displayed (#28558)

Release Notes:

- agent: Fix a bug where an inserted @mention did not show up as the one
that was selected
5757e352b0Bennet Bo Fenner committed on 4/11/2025, 2:04:03 AM· committed by GitHubparentc124838
2 files changedLine totals unavailable