The compose volume `jars` gets created as `<project>_jars` by Docker Compose, but JARDOCKERVOLUME tells the server to mount `cameleer-jars` on deployed app containers. These are different Docker volumes, so the app JAR was never visible inside the app container — causing ClassNotFoundException on startup. Fix: add `name: cameleer-jars` to the volume definition so both the server and deployed app containers share the same named volume. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>