Enable self-interested distributed harvesting

Container image and model where users can host a harvester on their own infrastructure. Code to ensure local harvest is used as a priority for own components harvested locally, and share the scans back to ClearlyDefined

No files, tests, or entry points are named. Start by clarifying the container image, model, and local harvesting flow, then identify where locally harvested components are prioritized and where scans are shared back to ClearlyDefined. Done should include a self-hostable harvester and verified local priority plus scan sharing.

Written by the indexing model from the issue text.