[Commerce] Ingest Etsy sold orders CSV export

[Nickel85]

Goal

Add an import path for Etsy sold order CSV exports like EtsySoldOrders2026.csv.

Source Shape

Observed columns include:

• Sale Date
• Order ID
• Buyer User ID
• Number of Items
• Payment Method
• Date Shipped
• Currency
• Order Value
• Coupon Code
• Coupon Details
• Discount Amount
• Shipping Discount
• Shipping
• Sales Tax
• Order Total
• Card Processing Fees
• Order Net
• Adjusted Order Total
• Adjusted Card Processing Fees
• Adjusted Net Order Amount
• Order Type
• Payment Type
• SKU

Acceptance Criteria

• Parses Etsy sold-order CSV exports without requiring the Etsy API.
• Normalizes dates, currency, order totals, discounts, fees, shipping, tax, and net values.
• Stores order-level records with stable order IDs and import provenance.
• Redacts or avoids storing unnecessary buyer PII in analytics views.
• Detects duplicate imports by order ID and source file fingerprint.
• Reports import counts, skipped rows, malformed rows, and duplicate rows.
• Adds validation fixtures based on representative headers from the sample export.

Out Of Scope

• Listing-level recommendations.
• Ad recommendations.
• Etsy API connectivity.