Server Versioning

[olaservo]

See: https://github.com/orgs/modelcontextprotocol/discussions/340

Edited notes from Tadas in #working-group-ideation:

I think we should probably merge this idea with the work on the registry -- we have been planning a notion of server.version_detail there and I think it will probably be worth taking that and putting into the spec as you are proposing.
Probably will make sense to keep this a separate proposal, just saying we'll want to align the shapes and maybe adjust the registry to match where we land with your thinking here

I think it will be worth keeping an eye on where version is going in this shape and maybe combining any thinking that goes into there. The current code looks like this Could be good to try to make sure your out-of-registry perspective is included as that forms

Also a 2nd hand note from Darren via #registry-wg:

Suggestion: He thinks we should maintain a separate version number within the registry per-mcp-server and not tie it to the canonical registry

Should follow up on the reasoning behind ^^

[olaservo]

Adding link to relevant PR convo:

modelcontextprotocol/registry#3 (comment)

[olaservo]

Full disclosure, I'm still trying to decide if this falls more into 'personal pet peeve' or 'real problem' territory. My intention sometime this week is to put together more concrete examples of related concerns to share with the group.