Add /v1/activity/daily endpoint returning per-day event counts via
generate_series + LEFT JOIN. Frontend renders an SVG contribution
graph with circles colored by quantile-based thresholds. Clicking a
day navigates to /activity/YYYY-MM-DD showing that day's events.
New /activity/:timespan route parses single dates (YYYY-MM-DD) and
ranges (YYYY-MM-DD..YYYY-MM-DD) from the URL to initialize the
activity timeline filter.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
