requireEncryption

When true, refuses to build a com.datastax.oss.driver.api.core.CqlSession unless enabled is also true -- fails fast with io.kandra.core.exception.KandraSchemaException before any connection attempt. Defaults to false: SSL itself is opt-in (enabled defaults to false), so defaulting this to true would break every default KandraConfig that doesn't touch the ssl { } block at all. Turn this on explicitly in deployments where TLS must never accidentally be left off -- e.g. a staging/prod config bundle that sets ssl { enabled = true; requireEncryption = true; ... } as a guard against that enabled line being dropped later, or an environment-variable override silently disabling it. (GH #78 / ISS-070 -- this field used to be declared but never enforced at any default; enforcing it at its old default of true would have been a breaking change for every non-SSL deployment, which is why the default moved to false alongside adding real enforcement.)