StressLevelZero/Custom-URP — reverse-engineered prompt

I want a Unity package that gives me a custom setup for the Universal Render Pipeline, with the main things already wired up so I can drop it into a project and start using it. Make it feel like a real reusable package, not just a loose shader demo.

It should include the render side pieces, some custom shaders and shader library code, useful presets, a few sample textures or resources, and editor tools that make setup easier inside Unity. I also want the runtime parts separated cleanly from the editor only parts, plus basic tests so it is not fragile.

Please make sure it works like a normal Unity package with sensible metadata and docs for how to install it, set it up, and use the included materials and presets. If there are mod or extra resource folders in the project, keep those organized and usable too. Look up current Unity and URP package conventions online if you need to.