Steps to Reproduce

0. Run coder server (not --dev which cleans up on interrupt)
1. Create a workspace using e.g. the docker template
2. Stop coder server
3. Update coder server
4. Restart coder server
5. Observe old agent reconnects without indication

Expected

There should be some indication that the connected agent is a different version than the server.

• The agent would report its version
• The server would log the agent version when it connects (possibly warn of version mismatch)
• The server would store agent version in database
• coder list would show outdated agent status
• The web UI would show outdated agent status (possibly add an option to trigger an update, how that would work in practice is TBD)

Actual

There is no indication of possible server/agent version mismatch.

Notes

I believe this will be important in the future to ensure we're not debugging issues that only happens during mismatches between the versions. Ideally patch and minor version mismatches would be safe/backwards compatible, but I doubt this will always be the case.