Secure Kubernetes Multi-Tenant Trading Platform Deployment

Design a Kubernetes deployment configuration for a multi-tenant financial trading platform using Nest.js that implements strict namespace isolation, network policy segmentation, and role-based access control (RBAC). The solution must support dynamic scaling of microservices, include comprehensive security policies preventing cross-namespace communication, and integrate with a financial-grade authentication mechanism using Kubernetes secrets management. Include TypeScript type definitions for your deployment configuration and demonstrate how you'll handle potential race conditions during horizontal pod autoscaling.