Preview stack is up

This is a placeholder web-client, not the Matiks app. It exists to prove the deploy path: deployer → compose → Traefik → TLS → routing.

Backend routes served by this same host:

• /api and /v1 → main-server:4000
• /ws → websocket-server:8080

Replace this image with a real Expo bundle once EXPO_PUBLIC_* config exists.