Team expense tracker with receipts

Build an expense tracker for a small team.

Core features:
1. Employees submit expenses with receipt photo + category
2. OCR the receipt (merchant, amount, date)
3. Manager approval flow
4. Export to CSV for accounting
5. Monthly report per project / per employee

Data: expenses, receipts, approvals, projects.
Must-haves: RLS (employee sees own, manager sees team), signed URLs for receipts.