Compact one-row strip: correction rate with count, median time to first
edit, and the top reworked file, plus one coaching note derived locally
with the same thresholds and copy as the CLI's workflow-insights
buildCoachingNotes. Decodes two new optional payload blocks
(current.workflow and current.topReworkedFiles), so payloads from older
CLIs still parse. The section hides entirely when there is no signal and
individual stats never render as zero placeholders. It reads the store's
current payload, so it follows the selected agent tab automatically.
Adds unit tests for the duration formatter, note selection, model
derivation, and payload decoding.
Co-authored-by: reviewer <review@local>
