Observe claimed prepared executions

convert.go

@@ -18,6 +18,11 @@ func toDomainRunRequest(req RunRequest) (domain.RunRequest, error) {
 	if err != nil {
 		return domain.RunRequest{}, err
 	}
+	var observer domain.ExecutionObserver
+	if req.Observer != nil {
+		callback := req.Observer
+		observer = func(event domain.ExecutionEvent) { callback(fromDomainExecutionEvent(event)) }
+	}
 	return domain.RunRequest{
 		PromptID:         req.PromptID,
 		PromptVersion:    req.PromptVersion,
@@ -30,6 +35,7 @@ func toDomainRunRequest(req RunRequest) (domain.RunRequest, error) {
 		Validation:       toDomainOutputContractPtr(req.Validation),
 		AppendedMessages: appendedMessages,
 		TransientRetries: copyIntPtr(req.TransientRetries),
+		Observer:         observer,
 	}, nil
 }