Webhooks deliver events to a URL you control. Register endpoints in the dashboard
or via `POST /webhooks`.
Each delivery includes an `X-Orbit-Signature` header: an HMAC-SHA256 of the raw
body using your signing secret. Compare it to a locally computed HMAC before
trusting the payload.
Respond with a `2xx` within 5 seconds. Non-2xx or a timeout triggers retries with
exponential backoff for up to 24 hours.