CChromebook Inventory Scaffold

Design tokens + fonts + keyframes are loaded. App UI lands next.

Repo scaffold is in place. Coming up:

Task #4 — main app shell (header + KPI strip + scan station + table)
Task #14 — Pages Functions implementations (currently stubbed 501)
Task #15 — admin CSV import page (/admin/import.html)
Task #17 — D1 create, schema apply, GitHub push, CF deploy