[Bug]: React-component-typescript docgen broken in new Vite project

[shilman]

Describe the bug

1. pnpm create storybook@next in an empty directory
2. Select React-TS
3. pnpm exec storybook add @storybook/addon-mcp

Verify that everything works as expected. Then update main.ts to use:

  typescript: {
    reactDocgen: "react-docgen-typescript",
  },

Manifest debugger will error:

NOTES:

• also an error in storybook@latest but more verbose
• no error with react-docgen or experimentalReactComponentMeta: true
• argTypes also broken in addon-docs

Reproduction link

no

Reproduction steps

No response

System

│  System:
│  OS: macOS 26.4
│  CPU: (10) arm64 Apple M1 Pro
│  Shell: 5.9 - /bin/zsh
│  Binaries:
│  Node: 24.11.0 - /usr/local/bin/node
│  Yarn: 1.22.22 - /usr/local/bin/yarn
│  npm: 11.6.1 - /usr/local/bin/npm
│  pnpm: 9.9.0 - /Users/shilman/Library/pnpm/pnpm <----- active
│  Browsers:
│  Chrome: 146.0.7680.165
│  Firefox: 149.0
│  Safari: 26.4
│  npmPackages:
│  @storybook/addon-a11y: ^10.4.0-alpha.5 => 10.4.0-alpha.5
│  @storybook/addon-docs: ^10.4.0-alpha.5 => 10.4.0-alpha.5
│  @storybook/addon-mcp: ^0.4.2 => 0.4.2
│  @storybook/addon-vitest: ^10.4.0-alpha.5 => 10.4.0-alpha.5
│  @storybook/react-vite: ^10.4.0-alpha.5 => 10

Additional context

No response