product-context.test.tsx failed with "localStorage.clear is not a function".
Root cause: Node 25 ships a global `localStorage` Web Storage stub that is
non-functional without --localstorage-file, and it shadows the test DOM
environment's storage. The two DOM tests also relied on `jsdom`, which was only
present transitively (not a tracker-web dependency) while the rest of the
monorepo standardizes on happy-dom.
- Add happy-dom as a tracker-web devDependency; switch the two `@vitest-environment
jsdom` tests (product-context, command-menu) to happy-dom.
- Add vitest.setup.ts that installs a real in-memory Web Storage over Node 25's
non-functional stub when the active localStorage/sessionStorage lacks the
Storage API; wire it via test.setupFiles.
Verified: full tracker-web suite 230/230 (was 228/2).
Generated with [Devin](https://cli.devin.ai/docs)
Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>
