The test script runs vitest and imports from @testing-library/react and
@testing-library/jest-dom, but none of these were listed as devDependencies.
Adds vitest ^3.0.5 and all required @testing-library packages matching other
plugin repos in the org.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
The shared plugin-ci.yaml workflow uses `cache: npm` in setup-node
and runs `npm ci`, both of which require a lock file. Without it,
CI fails with "Dependencies lock file is not found".
Co-Authored-By: Paperclip <noreply@paperclip.ing>