[Typescript] `browser.runtime.getURL` doesn't respect the unlisted css

Describe the bug

While npx wxt prepare generates the types folder, it doesn't generate types for browser.runtime.getURL for the unlisted css (documentation).

Also, i noticed that there is an error in the description of the documentation about unlisted css.
entrypoints/{name}.(css|scss|sass|less|styl|stylus) will generates /assets/{name}.css, not /{name}.css.

Reproduction

This is a reproduction to inject css file into main world.

/entrypoints/main-world.css is the target css file will be injected into the main world.

injectCss(browser.runtime.getURL('/assets/main-world.css'))
// injectCss just creates the link element and insert into document head

The generated types for the browser.runtime.getURL looks like:

declare module "wxt/browser" {
  export type PublicPath =
    | ""
    | "/"
    | "/background.js"
    | "/content-scripts/mycontent.js"
    | "/icons/128.png"
    | "/icons/16.png"
    | "/icons/32.png"
    | "/icons/48.png"
    | "/inject.js"
  type HtmlPublicPath = Extract<PublicPath, `${string}.html`>
  export interface WxtRuntime {
    getURL(path: PublicPath): string;
    getURL(path: `${HtmlPublicPath}${string}`): string;
  }
}

The unlisted script (inject.js) is properly generated, but unlisted css is not.

Steps to reproduce

No response

System Info

System:
    OS: Windows 10 10.0.19045
    CPU: (6) x64 Intel(R) Core(TM) i5-9400 CPU @ 2.90GHz
    Memory: 14.48 GB / 31.83 GB
  Binaries:
    Node: 20.18.0 - C:\Program Files\nodejs\node.EXE
    npm: 10.8.2 - C:\Program Files\nodejs\npm.CMD
    pnpm: 10.10.0 - ~\AppData\Local\pnpm\pnpm.CMD
  Browsers:
    Edge: Chromium (133.0.3065.69)
    Internet Explorer: 11.0.19041.4355
  npmPackages:
    wxt: ^0.20.0 => 0.20.6

Used Package Manager

pnpm

Validations

• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

Start by running npx wxt prepare and inspect the generated types folder, comparing the existing inject.js entry with the unlisted CSS case described in the issue. Update the generated PublicPath behavior so the CSS asset path is represented, and correct the unlisted CSS description at the linked documentation page.