Aggregate task_log + sessions by human_id over the last N days.

project_id optional — omit to roll up across all projects. Returns {period_days, humans:[...], active_count}. Used by the Team tab cards, swimlane timeline, and standup digest.

RT-TI-005 (wave 2) — /team/summary is outside the /projects/{uuid} middleware and, without a project_id, rolls up every project's task log. A project-scoped member must therefore name a project inside their own scope (the dashboard's Team tab always does); an omitted or foreign id is a 403, never a workspace-wide fallback (same rule as /control-plane/proposals).