IA-976 : `feat: Add cardLast4 enrichment to InvoiceDTO`

MR Description

Summary

Extends InvoiceDTO with the parent's default card last 4 digits, fetched from the local PaymentDetailsRepository during DTO enrichment.

Changes

InvoiceDTO

• Added cardLast4 field (String) InvoiceDTOEnricher
• Injected PaymentDetailsRepository
• Added a second enrichment block that looks up the parent's default active card (defaultCard = true, active = true) and sets cardLast4 on the DTO
• Each enrichment block is independently wrapped in try/catch to prevent a card lookup failure from breaking parent info enrichment PaymentDetailsRepository
• Added derived query method:

  Optional<PaymentDetails> findByParentUuidAndDefaultCardTrueAndActiveTrue(String parentUuid);