With what you’ve posted, both the *.java and *.class file are generated into the classes directory and included in the jar / on the classpath.
For the curious, doodad = Annotation Processor
Taking what you have, I added an example entity in the entity project and usage of it in a “project B”, both directly copied and pasted from the querydsl website and everything works as expected (minus the additional, but non-breaking inclusion of the *.java file).
Considering the most basic example project with querydsl extrapolated from your post works, you might be overlooking something impactful that’s not actually querydsl related.