Add stats dashboard page

[kimgh06]

Summary

• add /stats dashboard page
• poll the stats dashboard API for live summary, active cursors, uptime, color, tile, and event data
• render hourly connections as an SVG vector graph
• add a client make dev target

Validation

• npm run build

Notes

• Build still reports the existing cancelCurrentMovement hook dependency warning in src/components/canvas/index.tsx.