update db str

backend/README.md

@@ -5,6 +5,12 @@ FastAPI backend for Grateful Journal - a private-first gratitude journaling app.
 **Port:** 8001  
 **API Docs:** http://localhost:8001/docs
 
+## 📚 Documentation
+
+- **[REFACTORING_SUMMARY.md](./REFACTORING_SUMMARY.md)** — Overview of database schema refactoring
+- **[SCHEMA.md](./SCHEMA.md)** — Complete MongoDB schema reference with examples
+- **[MIGRATION_GUIDE.md](./MIGRATION_GUIDE.md)** — Step-by-step migration instructions
+
 ## Quick Start
 
 ### 1. Prerequisites
@@ -47,7 +53,7 @@ FRONTEND_URL=http://localhost:8000
 - **`main.py`** — FastAPI app, CORS, route registration, lifespan events
 - **`config.py`** — Settings management (environment variables)
 - **`db.py`** — MongoDB connection (singleton pattern)
-- **`models.py`** — Pydantic data models
+- **`models.py`** — Pydantic data models (ObjectId support, encryption metadata)
 - **`routers/`** — API endpoints
     - `users.py` — User registration, profile updates, deletion
     - `entries.py` — Journal entry CRUD, date filtering