Problem:

When running a clean installation of the project without generating a build using stencil build, the following error is thrown:

[vite] (client) Pre-transform error: Could not find the output file
  Plugin: unplugin-stencil
  File: /Users/git/unplugin-stencil/playground/components/my-component/my-component.tsx

[vite] Internal server error: Could not find the output file
  Plugin: unplugin-stencil

This error occurs because there are no build files present. The following code explicitly throws an error when the file is not found:

const exists = await compiler.sys.access(compilerFilePath)
      if (!exists)
        throw new Error('Could not find the output file')

Fix

Updated the logic to allow storybook dev to run even if the Stencil build output is missing. This ensures that developers can start Storybook in a clean state without requiring a prior stencil build.