If we do care about the delta in security model between the web and other platforms, then we could build some kind of code bundling and signing mechanism for we

If we do care about the delta in security model between the web and other platforms, then we could build some kind of code bundling and signing mechanism for web applications, perhaps with some kind of transparency layer on top to make the code publicly auditable and make it harder to target specific users with malicious code. A bundling/signing/transparency solution for the web could probably be built out of some of a collection of mechanisms that already exist or have at least been explored. Related ideas include Subresource Integrity, Isolated Web Apps, Signed Exchanges and Web Packaging, Meta’s Code Verify extension, and source code and supply chain transparency proposals. Incidentally, I've actually just recently developed a solution to this exact problem: https://www.websign.app https://www.websign.app. WebSign started a while back as an internal framework used by the Cyph E2EE messenger (https://www.cyph.com https://www.cyph.com), and @eganist and I gave a talk that covered part of the TOFU architecture at Black Hat and DEF CON. Now there's a static web hosting service built around it for others to use, which takes care of bundling and code signing during deployment. If anyone here has a use case for it, we're looking for pilot customers now. Just shoot me an email at ryan@cyph.com.