Return period-over-period trend series for the productivity score, focused time, in-tab activity level, and the productivity-class focused-time mix, bucketed by day (default) or week in the optional tz (else UTC), for a member (user) or across one or more groups (groups), else the whole organization. Also returns totals for the selected window and the immediately-preceding equal-length window for period-over-period deltas. Re-aggregates existing page-session spans (no new capture). Restricted to organization admins/managers and gated by the activity-tracking flag.