Tags should have a TTL unless explicitly mentioned to keep forever

The tags listed in versions list should go away after a certain time.

Often people forget to clean them.

Maybe we can update the naming scheme of tags to specify ttl or something to explicitly tell us to keep them forever.

The issue does not name files, tests, or entry points. Start by locating how tags are listed in versions and how tag cleanup is handled, then define and document a TTL and an explicit keep-forever convention; done means expired tags are removed while marked tags remain.

Written by the indexing model from the issue text.