Submission

A run to queue (design 4.55): input for thread threadId, run by the agent agentId for tenantId, treating a busy thread as policy says, with at most maxAttempts attempts (RunQueueSettings.maxAttempts when built by RunSubmitter). A submissionKey makes the submit idempotent: a second submit with the key of an entry the store still holds returns that entry's ticket, and a different submission under the key is refused (QueueError.SubmissionKeyReused).

apply and the with* setters throw IllegalArgumentException for maxAttempts below 1; Submission.of returns it as a ValidationError.