Is there anyone created Sonar rules to access that @Inject annotations done on Axon components (like CommandGateway are marked as transient ?
Daniel,
although we do use SonarQube for our software, and you can see the analysis of all AxonFramework projects here, we have not yet delved into custom rules. I’m unaware of anyone else doing this currently, so if you want to have a go at it, please do! 
Cheers,
Bert Laverman