This sounds so much more appealing to me than github and co. Unfortunately I guess there's no multibillion dollar exit in the cards in this case.

Has there been any thought about how this might interact with centralized-ish hosting? For example. Suppose a large project chose to use a radicle repo as its "blessed" point of coordination. Being a major project of course there's a mirror on (at minimum) github that points back to a web page (presumably the radicle app) for filing issues, collab, wiki, whatever.

So a user that doesn't have any interest in learning about radicle wants to file an issue using the web app. When I glanced at the heartwood repo it seems to be read only with no indication of being able to log in (that's entirely unsurprising ofc). How much work / community welcome / etc is there likely to be for a project to offer a usable web front end, presumably leveraging a solution such as OIDC? Basically being able to "guest" users of centralized platforms in to the project so that they can collaborate with near zero overhead.

As a motivating example consider outfits that want to self host a git forge but also want to offer centralized services to users. Communities such as KDE and SDL come to mind. Many of them have ended up migrating to github or gitlab over the years for various reasons but in an alternate reality it didn't have to be that way!

I realize I'm effectively asking "do you have thoughts about implementing a partially federated model" but hopefully you can see the real world usecase that's motivating the (otherwise seemingly unreasonable) question.

It's a valid question, and in fact there's quite some interest in adding write features to the web app. The current version of Radicle was designed with one user per node in mind, to get things off the ground. The process of relaxing this is currently ongoing. First, to multiple users per node, which would make use-cases like the one you are sketching viable. What we'd like to avoid is to hand the key to the server, in such case, and instead generate an Ed25519 key in the browser, and sign there, with some web-compatible transport (HTTP? WebSocket?) in between. And that's just a bit more intricate than it sounds.