Share Gradle daemon between host and docker container

Not sure if this counts as “progress”, but here’s what I have done so far.

1. Share the Gradle home directory between host and container (~/.gradle in my case)
2. Turn Gradle daemon off using $GRADLE_HOME/gradle.properties
3. Instruct IDEA to build using Gradle, pointing to the (shared) GRADLE_HOME

This has addressed most of my woes, bar one:

IDEA invokes Gradle when build.gradle.kts is modified. This locks several files under GRADLE_HOME. The locks disappear, but only eventually. I’m not able to execute Gradle commands from within the container until that happens. In extremis you may need to kill the Gradle process running the host.