Function get_for_reflector 

pub(crate) async fn get_for_reflector(
    pool: &PgPool,
    reflector: &str,
    since: DateTime<Utc>,
) -> Result<Vec<ActivityRow>, Error>

Returns activity for a specific reflector since the given timestamp.

Results are ordered by observed_at DESC (most recent first). Used by the HTTP API and Tier 2 promotion logic to assess per-reflector activity levels.

Errors

Returns sqlx::Error on query failure.