Consider deprecating old store API

**Feature request**
It would be great to have encryption for handlers.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_encryption` with default `false`.

Start by reconciling the title about deprecating the old store API with the body’s request for encrypted handlers. No files, tests, or entry points are named; clarify the handler scope, encryption behavior, configuration location, and acceptance criteria before implementation.

Written by the indexing model from the issue text.