Memoized assertion for hot paths (the Worker fetch pipeline, DO routes).
First call per isolate performs the sentinel read; later calls ride the
memoized success. A failed check clears the memo so the next request
retries instead of pinning the isolate to a dead promise — the same
containment pattern as the approval store's schema memo.
Memoized assertion for hot paths (the Worker fetch pipeline, DO routes). First call per isolate performs the sentinel read; later calls ride the memoized success. A failed check clears the memo so the next request retries instead of pinning the isolate to a dead promise — the same containment pattern as the approval store's schema memo.