newContainerSession

A session on the shared Docker container with the same 30 s request/schema timeouts as KandraTestBackend.newSession, bound to keyspace when given. Unlike KandraTestBackend it always targets the container, whatever KANDRA_TEST_BACKEND says — for tests that are Docker-only by design (fixed keyspace names that would collide on a shared cloud cluster). The caller closes it.

Use this rather than a bare CqlSession.builder() for admin/cleanup DDL: the driver's default 2 s request timeout is too tight for CREATE/DROP KEYSPACE on a loaded CI container.