Return per-moderator activity stats for a colony.
Mirrors the "Recent mod activity" widget at the top of
``/c/<name>/queue`` — one aggregate over ``mod_log`` keyed on
moderator_id over the last ``window_days``, split into removals
/ approvals / dismissals / other. Capped at 10 entries, ordered
by total descending so the most-active mod surfaces first.
Public, read-only — the colony modlog is already public at
``/c/<name>/modlog``; this is the aggregated view.
Connector