Firestore Adapter for Better Auth

The `better-auth-firestore` package provides a robust Firestore adapter for the `Better Auth` authentication library, utilizing the Firebase Admin SDK. Currently at stable version `1.2.2`, it receives frequent updates, with several patch and minor releases in the past few months addressing bugs and adding features. This library acts as a drop-in replacement for `Auth.js` (formerly `NextAuth.js`) Firebase adapter, maintaining a compatible data shape, which simplifies migrations. Its key differentiators include built-in handling for Firestore-specific limitations, such as chunking `IN` queries that exceed the 30-value cap, and providing helper functions like `initFirestore` for easy setup and `generateIndexSetupUrl` for required index creation. It strictly targets Node.js 22+ and is designed for TypeScript projects, shipping with full type definitions. While it handles Firestore data storage, `better-auth-firebase-auth` is recommended for actual Firebase Authentication provider integration.