Ability to track timeEnd in Grafana

Currently, we're recording events in Grafana when a sync is triggered. However, it would be really helpful for us to also record when the sync completes. Grafana has the "timeEnd" property in their Annotations API, but this is currently not implemented:

https://grafana.com/docs/grafana/latest/developers/http_api/annotations/#create-annotation

Thank you!

Start by locating the existing Grafana annotation path used when a sync is triggered, then review Grafana's Annotations API documentation for the timeEnd property. The work is complete when the sync completion is recorded and the resulting annotation includes its completion time.

Written by the indexing model from the issue text.