Driven adapter: in-memory implementation of PlaybackPositionRepository.
Positions live in a Map. The state is ephemeral — it does not
survive a server restart. This is the SSR/test default used when a
client localStorage is not available; the browser-side adapter
(BrowserLocalStoragePlaybackPositionRepository) is the production
adapter for the Lesson Page.
Driven adapter: in-memory implementation of
PlaybackPositionRepository.Positions live in a
Map. The state is ephemeral — it does not survive a server restart. This is the SSR/test default used when a clientlocalStorageis not available; the browser-side adapter (BrowserLocalStoragePlaybackPositionRepository) is the production adapter for the Lesson Page.