jsdom replaces globalThis.AbortController with its own implementation;
Node.js undici-based fetch validates signals via instanceof against the
native AbortSignal, causing fetch to throw before MSW could intercept.
Fix via custom Vitest environment (tests/environment/jsdom-native-abort.ts)
that captures native AbortController/AbortSignal before jsdom patches them
and restores them after jsdom setup.
Also updates JournalBody test 004 to match component behaviour (headings
rendered as <p>) and removes debug console.log statements.
jubnl