Function create_archive 

pub async fn create_archive(
    state: &AppState,
    camera_ids: Vec<String>,
    from: Option<DateTime<Utc>>,
    to: Option<DateTime<Utc>>,
    incident_lock_only: bool,
    trim: bool,
) -> AppResult<BackupJob>

Build a .zip of the selected segments and record it as an on_demand_archive job. Enforces the archive size cap on the source footprint; runs inline (bounded by the job timeout) so the returned job already carries output_url.