- Add separate momentry_playground binary with distinct configuration
- Production (momentry): Port 3002, Redis prefix 'momentry:'
- Development (momentry_playground): Port 3003, Redis prefix 'momentry_dev:'
- Add SERVER_PORT and REDIS_KEY_PREFIX config via environment variables
- Replace all hardcoded Redis key prefixes with configurable values
- Create .env.development for playground environment settings
- Update .env with production defaults
- Add dotenv dependency for environment file loading
Configuration isolation allows running both binaries simultaneously
without port conflicts or Redis key collisions.
