- Fix Active Technicians: query users WHERE role='technician' instead of counting from visit data
- Interactive bar charts: hover tooltips show label+count, click drills down to filtered asset list
- Quick action icons: coin for Assets, Sites, Check-in replaces CSV export buttons
- No visit data: suggestion card with 'Add a Check-in' button
- No manufacturer data: hide section entirely when empty
- 30-second TTL cache on both backend (/api/stats) and frontend (loadDashboard)
- Add dashboard cache module with time-based invalidation
shawn