- Add second row of stat cards: classroom count, occupancy rate, attendance rate, monthly income
- Add ECharts line charts for attendance trend (30-day) and income trend (6-month)
- All fields sourced from existing GET /dashboard/stats response (Task 7.1 contract)
- Move backend/ to apps/server/ via git mv
- Move frontend/ to apps/admin/ via git mv
- Create packages/typescript-config/ with base, nestjs, and react-vite presets