speakers: wipe command also clears legacy agents/ label paths
`sol call speakers wipe` globbed only chronicle/*/*/*/talents/ for
speaker_labels.json + speaker_corrections.json. In practice every
historical segment stores those files under agents/ — talents/ is the
destination for new writes from apps/speakers/attribution.py. A real
dry-run on jer's journal reported 0 labels and 0 corrections when the
actual counts are 3360 + 96.
Cover both paths so the wipe catches historical and new-write artifacts.
Test fixture now creates both layouts and asserts counts of 2 in each
category.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>