Get Shared Data Summary

Aggregate counts across the consenting-user pilot population.

Used by the Overview "Research pilot" panel to render at-a-glance metrics that previously required visiting the Shared, Reported, and per-user Activity tabs separately.

Fields are deliberately conservative: only counts and a small leaderboard, never message bodies or memory. The bodies stay behind the existing per-conversation endpoints, which already PII-redact and audit-log every read.

consents_changed_this_week counts every user currently consenting whose data_sharing_consent_at toggled within the last 7 days. The OSS column ticks on every change (opt-in OR opt-out), so the count surfaces "consent state moved recently" rather than "first-time opt-ins". A user who toggles off and back on within the week still counts.

A heartbeat-error metric was deliberately excluded: the OSS heartbeat scheduler writes action_type of send | skip | cleanup and never error, so any "errors this week" count we built here would always be zero. If we want a real error signal in the future, it has to come from a different source (LLMUsageLog failures, the Reported queue, structured logs).