Add Vitest 4 with happy-dom, @vue/test-utils, and a single
test/storybook.test.ts that auto-discovers every story under
src/v2/lib and runs its play() via composeStories — no Playwright,
just composition-based interaction tests. 89 stories now smoke-pass
in CI.
Scripts: lint:fix (auto-fix), lint (now scoped to ./src/v2; v1 is
frozen), lint:all (legacy sweep), test, test:watch, test:ui,
storybook:test.
eslint.config.js gets argsIgnorePattern: "^_" so unused-by-design
parameters can use the underscore convention.
CI: new frontend.yml runs lint, test, build in parallel on
frontend/** changes; typecheck.yml bumped to Node 22 with cached
npm ci. Existing typecheck job preserved for branch protection.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
