Describe the enhancement:

The Elastic distribution of the OpenTelemetry Collector (aka Elastic Agent) should guarantee at least once delivery of logs.

Describe a specific use case for the enhancement or feature:

At the moment, Elastic Agent collects and ships logs using Filebeat. And Filebeat guarantees at least once delivery of logs.

What is the definition of done?

An end-to-end test proving that Elastic Agent running with an OTel Collector configuration — and therefore running an OTel Collector pipeline in the embedded OTel Collector — can collect logs from a file and ship them to Elasticsearch with an at least once delivery guarantee. That is, every log line present in the file should be indexed into Elasticsearch.