Set up Vitest + React Testing Library with one example test

[KonstantinMB]

The frontend has no test suite. Adding test infrastructure now — with one passing example test — unblocks all future test contributions and gives us something to gate CI on down the road.

What to do

• Add vitest, @testing-library/react, @testing-library/jest-dom, and happy-dom (or jsdom) to frontend/package.json as devDependencies
• Create frontend/vitest.config.ts that reuses the path aliases from vite.config.ts
• Add an npm test script (and npm run test:watch)
• Write one example test against a simple leaf component — suggestion: a Radix-wrapped UI primitive from frontend/src/components/ui/, or one of the smaller display components. Render it, assert something obvious (text content, a class, a callback firing)
• Update the README "Testing" section to mention npm test

Acceptance criteria

• cd frontend && npm test runs and the one test passes
• cd frontend && npm run build still works after the changes (no type regressions)
• Test file co-located with the component (Button.test.tsx) or under src/__tests__/ — your call
• Vitest is dev-only (not bundled into production builds)
• README mentions the new command

Why this matters

Once this lands, every future PR can add a test in 5 minutes. Right now nobody can, because there's no infrastructure. This is the kind of foundational change that compounds.

Scope

Touches 4–5 files. Estimated time: 1-2 hours.

Want to take this on? Comment below and I'll assign it to you.

[anuj8126]

Hi @KonstantinMB , I’d like to take this on.
I’ll set up Vitest + React Testing Library for the frontend, add one small example test, make sure cd frontend && npm test passes, verify npm run build, and update the README with the new testing command.