Implement smoke test for clients and servers

[jonathanhefner]

This commit adds tests/smoke-test.sh, which performs a smoke test of all clients and servers. The smoke test tests that the clients and servers run and that list tools is called.

This commit also adds a GitHub Actions workflow to run the smoke test on all pull requests and pushes to main.

For practicality, this commit modifies the TypeScript and Python clients to lazily initialize the Anthropic client, thus allowing tests to skip setting an API key. This change also provides a friendly error when users forget to set an API key.

🤖 Generated with Claude Code

[a-akimov]

Hi @jonathanhefner, could ypu please update the branch and merge all the conflicts, so that we can approve and merge it? Thanks!

[jonathanhefner]

@a-akimov Thanks for the reminder! Rebased! 😃

[a-akimov]

Hi @jonathanhefner , sorry, it still shows some conflicts - please take a look.

[a-akimov]

@jonathanhefner I resolved the conflict (it was a small one in package-lock.json) and approved your changes. But because I was the last one making a commit to resolve the conflict, I suppose now it needs your review and approval too. Kindly ask you to take a look to finally merge this PR as it adds a lot of value. Thank you.

[a-akimov]

@jonathanhefner Could you please look into this and approve too? I believe this is a very valuable addition to this repo and would be great to merge it before we continue with merging more PRs here.