feat: launch handler

[ThaUnknown]

Summary

adds a launch_handler, and a lanchqueue consumer

the goal of this is to have new URLs opened externally [or internally], create new tabs in the already open client, rather than open a new one, for example: some1 on discord sends a github link, extension catches it, opens diffkit, but instead it opens it as a new tab, or some1 on discord sends a diffkit link directly, then the browser handles that directly

More details in the spec: https://github.com/WICG/web-app-launch/blob/main/launch_handler.md

not familiar with the codebase so this maybe could be done better? idk

there are ways to do this without the launchqueue, via serviceworkers, but that's effort, and would require actually writing react code, which I'm 50/50 on

Test Plan

Creates dummy launch queue, since it's a native api

Screenshots

Not applicable

This was like 70% AI coded with supervision, because React, and god I hate React, feel free to deny the PR for that, but the general idea is there.

[ThaUnknown]

I overall heavily dislike the current manifest.json situation, imho it shouldn't be an asset, but instead be generated at runtime, for things such as theme colors, and other PWA features which require the origin to be specified