Applies each app's database changes safely, in order and once only, with a record of what ran.
Health: GET /api/ext/health. Every SAIG app and engine is called through /api/ext with its per-app key (x-saig-service-token + X-SAIG-App), as set out in the SAIG integration guide.
Part of SAIG Technologies, a trading name of Skylite Group Ltd.