loadJourney previously set loading=true unconditionally, causing the
JourneyDetailPage guard (if loading || !current) to unmount the entire
page tree on every background refetch — entry saves, settings saves,
trip link/unlink, contributor invite, delete, and WS realtime events
all triggered the full-page spinner flash.
Now loading is only toggled on cold loads (current?.id !== id).
Warm refreshes replace current silently so the hero, sidebar, map,
and timeline stay mounted throughout. Closes#673.
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