Scan engine optimization

We have made significant improvements to the scanner's target queue. We have reduced the timeout to 300 ms for invalid domains or email addresses, so they no longer cause delays for other scans. Additionally, we have added indexes to the database collections to speed up data processing. To save time and server traffic, we have also included projections that retrieve only the necessary fields from a document, rather than all fields. retrieve only the necessary fields from a document, rather than all fields.