sdlc-firestore-repository

Implement Firestore data access with an explicit collection design and the Repository Pattern over the google-cloud-firestore client. Use when creating collections, repositories, document layouts, or any Firestore CRUD operations. Triggers on Firestore, database, collection, document, data model, or data access requests. Never substitute client-side filtering for document/index design — always model access patterns as documents, subcollections, and composite indexes first.