Chat SDK Adds PostgreSQL State Adapter

Following Redis and ioredis, Chat SDK now supports PostgreSQL as a new production state backend. This allows teams already running PostgreSQL to manage subscription information, distributed locks, and key-value cache state without adding separate Redis infrastructure.

The new adapter uses the pg (node-postgres) library and operates via raw SQL queries. It provides functionality to automatically create the necessary tables upon first connection.

Key features include:

• Support for TTL-based caching
• Distributed locks across multiple instances
• Namespaced state management via configurable key prefixes