Add Multi-Language Card Support to PriceCharting Database and Marketplace Tracking

Summary
Add support for non-English card variants (French, German, Italian, Spanish, etc.) across the card database and marketplace ingestion pipeline.

Currently, non-English cards are often merged with English pricing data, which creates inaccurate market values and sales history. Platforms like eBay already expose language metadata for listings.

Scope

• Add language field to cards, listings, and sales records
• Support languages such as EN, FR, DE, IT, ES etc.
• Separate pricing/history by language
• Add language filters in search/UI

Acceptance Criteria

• Users can filter/search by card language
• Price charts/history are language-specific
• eBay listings are correctly classified by language
• English and foreign-language sales are no longer merged together

Example

• English Charizard and German “Glurak” should maintain separate pricing histories and market comps.