Function try_remove_non_owner 

pub async fn try_remove_non_owner(
    db: &SqlitePool,
    group_id: Uuid,
    user_id: Uuid,
) -> Result<bool, Error>

Atomically remove a non-owner member from a group. The role guard is folded into the WHERE clause so a member promoted to owner between an upstream check and this call is never silently kicked. Returns true if a row was deleted.

Errors

Returns Error::Database on delete failure.