Support deletion

Hi,

is there any chance to support at least product/category deletion? The sync seems to work well, but it does not find any "stale" items which would help us cleaning the projects. I can write down some usage details if needed, just wanted to check first.

No files, tests, or entry points are named. Start by reviewing the existing product and category synchronization behavior, then determine how stale resources and deletion safety should be represented. Done should include an agreed scope for deletions and verified behavior for the affected resources.

Written by the indexing model from the issue text.