[UR]015-INV- Invoices

As an authenticated user, I want to view my invoices with discount details and download them as PDF, so that I can keep records of my purchases.

Acceptance Criteria:

AC1 – Invoice list

Given I am logged in When I navigate to my invoices page Then a paginated table is displayed with columns: invoice number, billing street, invoice date, total, and a details link.

AC2 – Invoice detail

Given I click on an invoice Then the detail page shows:

invoice number, date, and total
billing address (street, postal code, city, state, country)
payment method and details
product line items (quantity, name, price, line total)

AC3 – Non-existent invoice

Given the invoice does not exist or does not belong to me Then a "not found" message is displayed.

AC4 – Discount on invoice

Given the invoice has a discount Then the detail page shows the subtotal, discount percentage and amount, and final total.

AC5 – Discounted line items

Given a line item has a discount Then the original price is shown with a strikethrough and the discounted price below.

AC6 – PDF download button

Given I am on the invoice detail page Then a "Download PDF" button is displayed.