Mock global.fetch in the test-connection test so it no longer hits the
real network. The route has a 10s fetch timeout, but the test used the
default 5s vitest timeout, causing intermittent failures when DNS/network
was slow. Add afterEach(vi.restoreAllMocks) to clean up between tests,
and reconcile the misleading "returns 400" test title to match the 200
assertion the route actually produces.
Co-Authored-By: Paperclip <noreply@paperclip.ing>