Testing fix for CVE-2026-40073

[yahmed-66]

closes # CVE-2026-40073

When reviewing the fix for the body size limit bypass in the node adapter,
I noticed the existing test suite only covered the updated code paths
(chunked encoding, valid Content-Length) but not the original bypass path.

This adds a test documenting that HTTP/1.1 requests with no Content-Length
and no Transfer-Encoding header return an empty body rather than processing
oversized input.

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