I'm grasping at straws, because what appears to have happened in the first screenshot is that the bundle for Perspective (prefixed/named perspective) is not available. The only way I can see that happening as a result of your module is if you're inadvertently colliding with that name.
Basic troubleshooting stuff:
Does it persist if you restart the designer?
Does it go back to normal if you uninstall your module?
Ah okay I have other helpful information here then. So across all of my project scope files, my attempts to import anything starting with "com.inductiveautomation.perspective" fail.
As you can see I'm currently "modlImplentation"ing "perspective.common" and "perspective.gateway". I've also tried applying "compileOnly" and "implementation", which didn't change the error lints in my IDE, but to be fair I haven't yet tried to open a designer and see yet. I'll go ahead and try those now.
At the time I thought maybe my IDE was wrong about its linting, as I was still able to build, upload the module without issues, and even see the component show up in the browser.
Additionally I should also mention that one potentially big difference between my project, and the example project is in the root's build.gradle.kts. We have a 'subprojects' block:
Well you're not going to be able to resolve those dependencies with our public Nexus maven repo commented out (the ignitionsdk stuff should all be compileOnly, by the way, because we're going to provide the dependencies for you at runtime).
But that's not (probably) the root cause of what you're seeing here.
Yeah, you shouldn't be declaring dependencies in subprojects at the parent, because those dependencies don't make sense to (some) of the child projects.
You must be using cached local versions of these dependencies or something, because there's no way you're resolving the ignitionsdk dependencies without our public Maven repo.
Because in both the perspective-component example, and the repo you just linked, the maven repo isn't declared in any of the project-scope specific build.kts files. And I can see in both projects how they might be applying it globally in some way.