Build an invoice generator:
- Company details: name, address, logo placeholder, tax ID
- Client details: name, address, email
- Line items: description, quantity, unit price, tax rate
- Auto-calculate subtotal, tax, and total
- Multiple currency support (USD, EUR, GBP)
- Invoice number auto-increment (stored in localStorage)
- Due date and payment terms
- Notes/terms section
- Print-friendly layout
- Export as PDF (using browser print or jsPDF)
- Save draft invoices in localStorage
Professional, clean design. Put in ~/data/public/