AUDIT-059 round 15 — diagnostic. New cvar `audit_jit_prolog_r3_bytes`
(default 64 = existing behaviour, capped at 256, rounded up to 16B
multiple) controls how many bytes are dumped at host(r3) when the
audit_jit_prolog_pc probe fires. Set to 80 to capture audit-051's
stack-local struct at sub_82452DC0's r31+96.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>