parts_panel_viewed carried only opaque vehicle_id/category_id, so the
'0 parça' empty-catalog breakdown (and its rate-spike alert) couldn't say
WHICH vehicle/category was empty — useless for prioritising catalog backfill.
- parts-panel: add vehicle_label + category_name to parts_panel_viewed, and
fire a new empty_catalog_cta_clicked (with the same context) from the
empty-state button — a demand/abandonment signal per vehicle+category.
- schema-viewer: forward the two optional props to PartsPanel.
- vehicle category route: pass the existing vehicleLabel + data.name.
Best-effort labels (undefined on routes not yet threaded); parts_count
unchanged so existing insight/alert keep working.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
