Function repository_clear_watch_history 

pub async fn repository_clear_watch_history(
    manager: State<'_, RepositoryManagerWrapper>,
    handle: String,
    item_id: String,
) -> Result<(), String>

Erase the viewer’s watch history for an item.

Clears the played flag and the resume position; on a series or season the server applies it to everything inside. A series cleared this way is “never watched” again, so repository_get_series_current_episode returns its premiere. Requires the server — offline this fails rather than diverging local state the next sync would overwrite.

TRACES: UR-064 | DR-106