ESLint crashes when eslint-plugin-storybook is not installed

[haljac]

Problem

Running npm run lint fails with:

Error [ERR_MODULE_NOT_FOUND]: Cannot find package 'eslint-plugin-storybook'
imported from eslint.config.js

eslint.config.js uses a static import for eslint-plugin-storybook. If the package isn't in node_modules, ESLint completely crashes — it can't even lint non-Storybook files.

Root Cause

• eslint-plugin-storybook and other Storybook dependencies were added to package.json in commit dbed07d
• Developers who had node_modules from before that commit never re-ran npm install
• Worktrees start with empty node_modules, so they always hit this
• CI is unaffected (runs npm ci which installs everything)

Fix

Make the Storybook ESLint plugin a graceful optional dependency using dynamic import() with a try/catch fallback. If the package isn't installed, ESLint should skip Storybook rules but still work for everything else.