Improves styling for conversation header

Editor assessment

The subject names the area, styling for the conversation header, but 'Improves styling' is the contentless form: which properties changed and why are left to the diff. Chore is a loose type for visual work where style fits better, though the straddle is arguable. No scope, no body, no footers, only a Co-authored-by trailer. The trailing pull-request number is conventional. Hygiene is otherwise fine: imperative shape, no trailing period, no junk. Understandable as an area label and unhelpful as a description.