* fix: Apply max_connections configuration to Redis async client
- Add max_connections to available Redis cluster kwargs
- Add connection_pool parameter to get_redis_async_client()
- Pass connection_pool to Redis client if provided
- Prevents Redis connection exhaustion under high load
* test: Add tests for Redis max_connections feature
- Test max_connections is included in cluster kwargs
- Test connection_pool parameter is properly passed to async client
- Test async client works without connection_pool parameter
All 3 tests pass successfully
soo-jin.kim