bug: Storybook example doesn't test browser apis

[stevezhu]

If you try to use browser apis in storybook, there's a bug during the build. There should be a test to make sure that the WxtVitest() plugin mocks are actually working with storybook.

✘ [ERROR] Could not resolve "../pkg"

    ../../node_modules/.pnpm/lightningcss@1.29.2/node_modules/lightningcss/node/index.js:17:27:
      17 │   module.exports = require(`../pkg`);
         ╵                            ~~~~~~~~

✘ [ERROR] No loader is configured for ".node" files: ../../node_modules/.pnpm/fsevents@2.3.3/node_modules/fsevents/fsevents.node

    ../../node_modules/.pnpm/fsevents@2.3.3/node_modules/fsevents/fsevents.js:13:23:
      13 │ const Native = require("./fsevents.node");
         ╵                        ~~~~~~~~~~~~~~~~~

1:08:16 PM [vite] (client) error while updating dependencies:
Error: Build failed with 2 errors:
../../node_modules/.pnpm/fsevents@2.3.3/node_modules/fsevents/fsevents.js:13:23: ERROR: No loader is configured for ".node" files: ../../node_modules/.pnpm/fsevents@2.3.3/node_modules/fsevents/fsevents.node
../../node_modules/.pnpm/lightningcss@1.29.2/node_modules/lightningcss/node/index.js:17:27: ERROR: Could not resolve "../pkg"
    at failureErrorWithLog (/Users/<user>/Development/temp/examples/storybook/node_modules/.pnpm/esbuild@0.25.2/node_modules/esbuild/lib/main.js:1477:15)
    at /Users/<user>/Development/temp/examples/storybook/node_modules/.pnpm/esbuild@0.25.2/node_modules/esbuild/lib/main.js:946:25
    at /Users/<user>/Development/temp/examples/storybook/node_modules/.pnpm/esbuild@0.25.2/node_modules/esbuild/lib/main.js:1355:9
    at process.processTicksAndRejections (node:internal/process/task_queues:104:5)

For example:

https://github.com/wxt-dev/examples/blob/main/examples/storybook/components/test-Button.stories.ts

import type { Meta, StoryObj } from "@storybook/react";
import { fn } from "@storybook/test";
+ import { browser } from "wxt/browser";

import { Button } from "./Button";

+ console.log(browser);

// More on how to set up stories at: https://storybook.js.org/docs/writing-stories#default-export
const meta = {
  component: Button,
  parameters: {
    // Optional parameter to center the component in the Canvas. More info: https://storybook.js.org/docs/configure/story-layout
    layout: "centered",
  },
  // This component will have an automatically generated Autodocs entry: https://storybook.js.org/docs/writing-docs/autodocs
  tags: ["autodocs"],
  // More on argTypes: https://storybook.js.org/docs/api/argtypes
  argTypes: {
    backgroundColor: { control: "color" },
  },
  // Use `fn` to spy on the onClick arg, which will appear in the actions panel once invoked: https://storybook.js.org/docs/essentials/actions#action-args
  args: { onClick: fn() },
} satisfies Meta<typeof Button>;

export default meta;
type Story = StoryObj<typeof meta>;

// More on writing stories with args: https://storybook.js.org/docs/writing-stories/args
export const Primary: Story = {
  args: {
    primary: true,
    label: "Button",
  },
};

export const Secondary: Story = {
  args: {
    label: "Button",
  },
};

export const Large: Story = {
  args: {
    size: "large",
    label: "Button",
  },
};

export const Small: Story = {
  args: {
    size: "small",
    label: "Button",
  },
};