Function open_demo 

pub async fn open_demo(
    path: &Path,
    user_templates: Option<Vec<DcsTemplate>>,
    retention_days: Option<u32>,
) -> Result<SqlitePool>

Opens the Demo database without running the Full-mode live-orphan recovery sweep.

Demo uses visitor-owned simulator runs only; its recovery and capability policy is intentionally separate from live OPC DA recovery.