Add MongoDB Integration for Memory Storage

[eyenpi]

Overview

Implement MongoDB adapter as an alternative storage backend for scalable and distributed memory storage.

Requirements

• Create MongoDBStore implementing BaseStorage interface
• Add features:
  • Async CRUD operations
  • Index optimization for message queries
  • TTL support for message expiration
  • Sharding support
  • Connection pooling
• Support MongoDB Atlas integration

Technical Details

• Collection schema design:
  • Messages
  • Embeddings
  • Metadata
  • Indexes for common queries
• Environment configuration
• Connection management
• Error handling and retries

Acceptance Criteria

• MongoDB adapter implementation
• Connection pooling and error handling
• Performance tests (read/write latency)
• Unit and integration tests
• Documentation with configuration examples