setup

Prerequisites: 1. Confirm Storybook exists (`package.json`, `.storybook/`). If not, switch to `$storybook:init`. 2. Storybook must be 11.0 or later. An 11.0 prerelease (`11.0.0-alpha.x`) or a canary build (`0.0.0-pr-*`) also counts. If it is older, or upgrade/repair is needed first, switch to `$storybook:upgrade` and come back here afterwards. Treat a request to set up or install Storybook as approval to perform any required Storybook upgrade. For other requests, switch only after the user explicitly approves an upgrade. Run `npx storybook skills setup` from the project root (or the Storybook package in a monorepo). **Follow the printed Markdown precisely.** Do not substitute your own plan.