Apply safeJson's opt-in maxBytes ceiling to the body-accepting batch
and export routes that lacked one. The cap measures the raw text
before JSON.parse, so an over-limit payload returns a clean 413
without buffering onto the heap.
- workouts/batch: reuse the existing 5 MB ceiling so chunked uploads
with no Content-Length are bounded too.
- measurements/batch: 4 MB — an order of magnitude above a 500-entry
batch's few-hundred-KB worst case.
- export/health-record: 64 KB — the selection payload is small and
bounded.
Each cap is a DoS ceiling sized well above any legitimate payload,
never a tight bound on a real batch.
Marc-André Bombeck
48f20f4622