Describe the bug

This affects at least @storybook/react-vite.

After updating from v10.1.11 to v10.2.0 or above, using the Primary or Controls doc blocks within an .mdx component documentation page will silently fail, rendering the blocks empty without visible errors.

Reproduction link

https://stackblitz.com/edit/github-lp7rxyeq?file=src%2Fstories%2FButton.mdx

Reproduction steps

Simplified example using the untouched Button component from storybook.new:

// Button.mdx
import { Meta, Primary, Controls } from '@storybook/addon-docs/blocks';
import * as Stories from './Button.stories';

<Meta of={Button} />
<Primary />
<Controls />

System

│  System:
│  OS: macOS 26.2
│  CPU: (10) arm64 Apple M1 Pro
│  Shell: 5.9 - /bin/zsh
│  Binaries:
│  Node: 24.13.0 -
│  /Users/.../bin/node
│  Yarn: 1.22.22 -
│  /Users/.../bin/yarn
│  npm: 11.6.2 -
│  /Users/.../bin/npm
│  pnpm: 10.28.2 -
│  /Users/.../bin/pnpm <-----
│  active
│  Browsers:
│  Chrome: 144.0.7559.133
│  Firefox: 147.0.3
│  Safari: 26.2
│  npmPackages:
│  eslint-plugin-storybook: 10.2.8 => 10.2.8

Additional context

Working example with Storybook downgraded to v10.1.11: https://stackblitz.com/edit/github-lp7rxyeq-hz1w5yso?file=src%2Fstories%2FButton.mdx