Additional lens

Index: swival/audit.py
--- swival/audit.py.orig
+++ swival/audit.py
@@ -2752,6 +2752,7 @@ _PHASE45_LENSES = (
     "Lens: reachability. Concentrate on whether an untrusted actor can actually reach this code path under realistic deployment. If the only path runs through trusted, admin, or self-invoked code, it is a false_positive.",
     "Lens: threat-model fit. Concentrate on whether this matters in the project's expected threat model. A self-inflicted issue, or one only the operator can trigger, is not a vulnerability even when the code is genuinely wrong.",
     "Lens: severity and defense-in-depth. Concentrate on whether the claimed severity is justified and whether an existing control already mitigates this. Recalibrate to the realistic worst case and treat redundant-hardening proposals as false_positive.",
+    "Lens: proof soundness. Concentrate on whether the Phase 4 reproduction reasoning actually demonstrates the claimed vulnerability. Look for assumed code paths not shown in the committed evidence, logical gaps between observations and conclusions, and circular reasoning. If the proof relies on speculation or asserts behaviour that is not demonstrated by the code, it is a false_positive.",
 )
 
 _PHASE45_WORKED_EXAMPLE = """\
