I'm very excited to report that after another couple sessions of hacking on the plugin code, I now have a working plugin that can do search and display each per-note hit on its own result line with highlighting of the matched text!
Still doing some fiddling around with the search behavior, and I'll have to figure out how to manage hiding and showing the webview panel on command, but this is pretty much what I want to have!
I'll try to get the current WIP cleaned up and published in the near future!
Published! Don't know how long it takes for the Joplin plugin repository to scrape NPM and update, but here's the repo for my plugin:
I'm also sure there's a ton of other search config options that could be added, but this would do for starters.