Add little labels for sector someone cames from

We aren't all tech people running the show. It would be nice to point to that in a lightweight visual way. We could pull it from a Slack profile field, or just manually edit it in spreadsheet.

Review the generated embeddable people list and the available Google Sheet or Slack profile fields first. Define which sector source and label presentation are in scope, then verify that the chosen sector information appears consistently in the generated list.

Written by the indexing model from the issue text.