[improve] Code quality: remove stale test files and unused test devDependencies

[github-actions]

What

Remove the stale legacy test infrastructure that was left over from the Vue CLI era: the tests/ directory contents and the two unused test-related devDependencies (@types/jest and @vue/test-utils).

Why

The unit and e2e test files in tests/ have not been runnable since the Vite migration:

• tests/unit/example.spec.ts — imports shallowMount from @vue/test-utils and references a msg prop that no longer exists on HelloWorld.vue. There is no npm run test:unit script in package.json and no jest configuration.
• tests/e2e/ — a Nightwatch e2e test suite with no corresponding npm script or Nightwatch dependency installed.

Because these tests can never be executed, the two devDependencies they require serve no purpose:

Package	Size	Why unused
@types/jest	~2 MB of types	No jest config, no test runner
@vue/test-utils	~1 MB	Only referenced by stale spec file

Keeping them adds unnecessary weight to npm install, bloats package-lock.json, and expands the surface area for npm audit security advisories.

Note: jest.config.js removal is already proposed in issues #126 / #133. This issue addresses the complementary changes: removing the actual test files and their devDependencies.

Files to change

• tests/unit/example.spec.ts — delete (stale, non-functional)
• tests/e2e/ directory — delete entirely (no npm script, no installed runner)
• package.json — npm uninstall --save-dev @types/jest @vue/test-utils``
• package-lock.json — updated automatically by npm

Impact

• Cleaner npm install (removes ~3 MB of unused type definitions and test utilities)
• Reduces npm audit security scan surface
• Eliminates confusing dead code that implies tests exist when they don't
• Consistent with the spirit of [improve] Developer experience: remove legacy Vue CLI config files #126 / [improve] Developer experience: remove legacy Vue CLI config files #133 (removing legacy Vue CLI artifacts)

Verification

• npm run build passes
• npm run lint passes
• npm install no longer installs @types/jest or @vue/test-utils
• No existing PR conflicts

Generated by Continuous Improvement — Portfolio Site · ● 14.6M · ◷