Trigger reprocessing for multiple documents in parallel. Processing is always asynchronous (fire-and-forget). Errors per document are captured in the response but do not interrupt other documents_handlers.
Example response: [{"a1b2c3d4-e5f6-7890-abcd-ef1234567890": {"status": "processing"}}, {"b2c3d4e5-f6a7-8901-bcde-f12345678901": {"status": "error", "message": "failed to send cloud event"}}]