Fixes the offline-sync defects QA found on PR #120 (#237/#238/#220).
Blank-shell / white-screen on offline reload (HIGH):
- auth-query.tsx: the useCollabToken retry predicate read
`error.response.status` unguarded. Offline the collab-token POST rejects as
an axios NETWORK error (isAxiosError true, response undefined), so `.status`
threw an uncaught TypeError in the React Query retryer BEFORE React mounted,
white-screening every route. Extracted the predicate as `collabTokenRetry`
and guarded it with optional chaining (`error.response?.status === 404`).
- user-provider.tsx: gated the whole <Layout> on useCurrentUser() and returned
a bare `<></>` on any error, blanking every authenticated route offline even
when cached data existed. Now renders the cached app when a (stale) user is
present and an explicit OfflineFallback when there is no user to fall back on.
- query-persister.ts / make-offline.ts: persist and warm the ['currentUser']
query so the auth gate can hydrate offline (pinned pages now survive relaunch).
Offline structural create/move/comment silently lost on reload (HIGH):
- offline-mutations.ts: register setMutationDefaults (default mutationFns) for
stable mutation keys and tag useCreatePageMutation / useMovePageMutation /
useCreateCommentMutation with those keys. A paused mutation dehydrated to
IndexedDB while offline now has a mutationFn after reload, so
resumePausedMutations() replays it on reconnect instead of no-op'ing.
Tests (client vitest): collabTokenRetry no longer throws on a no-response
network error; UserProvider renders cached children / the offline fallback (not
a blank fragment) on a network error; a rehydrated paused create/move is
replayable via resumePausedMutations; currentUser persist-root coverage.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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