As of December 2020, there did not appear to be a straightforward way to host a flat file static website with automatically generated internal bidirectional links—this is a duct tape and baling wire solution.
Digital gardens go nearly all the way, and the Ness Labs process overview was extremely helpful. I stole heaps of stuff, including the basic idea, from there. (Thanks, Anne-Laure!)
But I wanted a structural separation between issue pages and topic pages, and to have bidirectional linking between them. So this is what I did:
Tool notes: TiddlyWiki is appropriate technology and I endorse it—it is simple, quick to learn, and easily extensible when extension is required. I briefly considered and rejected the idea of creating an Obsidian vault and turning that into a Blot site (no automatic bidirectional linking). I did not want to use Roam.