@morlay/session-persistence-rdb: RDB Persistent Session Backend for DeepSeek Harness

`@morlay/session-persistence-rdb` is an MIT-licensed plugin for DeepSeek Harness (DSH), designed to provide a SQLite- or PostgreSQL-based persistent session backend for `ctx.sessionPersistence`. The plugin implements the `PersistenceBackend<number>` interface via Drizzle ORM and reuses upstream coordinator and contract test suites. Before installation, a GitHub Packages access token must be configured in `.npmrc`, and it is crucial to scope the registry strictly to the `@morlay` namespace to avoid interfering with other dependency resolutions. Once enabled, the user...