8cce3a2165
/api/admin/stats accepts ?days= (clamped to 7/30/90, default 30) → passed to
admin_stats, which already windows visitors, retention, funnel, sharing, daily
trend, and the top lists by that span. Frontend adds a Window picker on the
analytics tabs (Overview/Content/Audience); changing it refetches and the
windowed labels ("Visitors (Nd)", "Last N days", "Returning visitors (Nd)")
follow. Corpus totals + source health are unaffected (not time-windowed).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>