Add daily usage trend charts with multi-metric toggles, overview vs user
analysis views, date-range filtering, and usage summary API for interval
and all-time totals.
Co-authored-by: Cursor <cursoragent@cursor.com>
Move admin backend into this repo (Express + MySQL on :8085) so npm run dev starts both API and Vite, with updated env defaults and Caddy config for gadm.tkmind.cn.
Co-authored-by: Cursor <cursoragent@cursor.com>