Reading this Geekflare article on 7 Best Self-Hosted Wiki Solutions for Small to Enterprise and they listed Outline, a Node.js wiki. This is more of a commercial solution though their software is open sourced and the Community Edition is free.

Outline

• blog/podcast (none) - doesn't seem to have it built-in nor any integration
• search (medium) - keyword or phrase, or matching (they have AI search for paid version; though results don't show context
• diagrams (none) - diagrams.net you just paste in the URL but I guess then it's a diagram saved externally.
• version history and diff (some) - there is version history but not sure there's diff

I guess Outline's differentiator is that they integrate to a lot of commercial solutions. But even then the list of integrations is not remarkable. I used their online documentation to find answers for my wiki criteria but their documentation looks nice yet has not that much info.

So in summary not a wiki that fits my needs.