Hmph. For some reason, permalinks no longer work as they used to. No idea why.
If anyone knows how permalinks work and how they are managed by WordPress, let me know or add your wisdom here. I’m not convinced that the magic “just happens” on. It has to be stored somewhere and I have no idea where.
So if you read this tripe in a feed reader, all is well. But if you browse or arrive via a search query, you’re outta luck.
[resolved]: the rewrite rules that make those pretty permalinks weren’t being flushed from the database where it is stored (in the table crank_options). Wiping out the value there and forcing WP to repopulate it did the trick. Details here.