perf(server): scan only appended transcript bytes for usage summaries (#9024)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
Co-authored-by: Theo Browne <me@t3.gg>
8f1ef8b9ebWout Stiens committed on 9/1/2026, 9:59:16 AM· committed by GitHubparent0bfb6df
6 files changedLine totals unavailable