REST API for Dr. Pixel Labs test harness communication
POST /api/labs/sessions - Create/join session with auto-discoveryGET /api/labs/sessions/:id/status - Check session status & heartbeatPOST /api/labs/sessions/:id/frames - Upload test frameGET /api/labs/sessions/:id/frames - Get pending framesPOST /api/labs/sessions/:id/captures - Upload captureGET /api/labs/sessions/:id/captures?frameId=:frameId - Get capture