iOS Bridge Control Plane

This service now exposes an API-first control plane. The interactive launcher lives in the React app root, not here.

• GET /servers lists ready Macs for an authenticated user
• POST /previews allocates a Mac, creates a session, and returns an embed JWT
• POST /admin/rebootstrap/{subdomain} queues a bootstrap rerun for one Mac

Point the React app at this origin with REACT_APP_CONTROL_PLANE_URL or window.__CONTROL_PLANE_API_URL__.