BE041 - Ranked and Paginated Product Search API

[shshwtsuthar]

Ticket

BE041 - Ranked and Paginated Product Search API

Description

Implemented the v1 backend product search API on top of BE040 search-field normalization.

• Added GET /api/products/search with normalized q, bounded limit, opaque query-bound cursors, and sanitized error envelopes.
• Uses an exact GTIN lookup for valid EAN-8, UPC-A, EAN-13, and GTIN-14 values; non-barcode queries make bounded reads against productNameSearch and brandSearch.
• Merges sources by canonical barcode and ranks exact name, name prefix, exact brand, and brand prefix matches deterministically, with barcode as the final tie-breaker.
• Returns compact product summaries, records only duration/outcome/result-count metrics, and does not log raw search terms.
• Added v1 contract documentation, unit coverage, and Firestore emulator coverage for exact and normalized prefix retrieval.

This PR targets feature/search-fields-normalization and should merge after BE040 / PR #206.

Testing

cd mobile-app
npm test -- --runInBand __tests__/productSearchApi.test.ts __tests__/firestoreProductSearchRepository.test.ts

cd ..
npx firebase emulators:exec --project demo-food-remedy-be041 --only firestore "npm --prefix mobile-app test -- --runInBand __tests__/firestoreProductSearchRepository.test.ts"

Results: 14 route/contract tests passed; the emulator-only test is skipped outside the emulator; the Firestore emulator repository test passed.

Checks

• All requirements of the ticket have been implemented, or I have commented on any exclusions
• Unit tests have been added or updated for any backend changes (if applicable)
• I have reviewed the Files Changed tab and verified it only contains relevant changes (comment if unsure about any)
• This PR has been reviewed and approved