Start Bulk Sync Execution
Starts a new execution of a bulk sync.
This endpoint returns the execution record immediately after the run is queued
or started. Use the execution ID with the bulk-sync execution endpoints if you
need to monitor progress in detail.
## Execution modes
- Set `test=true` to validate the sync without writing to the destination.
- Use `resync_mode` for destructive or full-refresh style reruns.
- `test` and `resync_mode` are mutually exclusive.
The legacy `resync` boolean is no longer accepted on this v5 endpoint. Send
`resync_mode` instead.
If another execution is already running, the endpoint returns `409 Conflict`.
