What is the ideal approach for one? Assuming you don't want it to be a public one (to avoid moderation headaches), and you want to avoid automated spam, and your page is a static site, what is the ideal way to incorporate something like that?

Maybe giscus

https://giscus.app/

It works for static sites, you just need to embed their script, and spam and moderation would be handled by GitHub.

I have a static blog with a public comments system using Disqus; it’s just a JS snippet and it works great. I’ve seen people (ab)using GitHub issues too, or even use gists for blog posts.

Shaming people for not leaving comments anyway, I infer. /s

I put my email address on these things. All spammers already have it anyway. I get some feedback.

Or a normal web form with a captcha will create minimal spam. Certainly sufficient for someone not famous.

Or you can have a google form. Either with or without google verifying the senders email address.