feat(agent): add executor evidence output contract

src/main/java/com/superbiz/agent/eval/DiagnosisTraceEvaluator.java

@@ -101,6 +101,8 @@ public class DiagnosisTraceEvaluator {
             failedChecks.add("reject output does not use degraded template");
         }
 
+        failedChecks.addAll(validateExecutorStructuredOutput(trace));
+
         Integer toolCallCount = trace.getToolInvocations() == null ? 0 : trace.getToolInvocations().size();
         Integer durationMs = trace.getSession() == null ? null : trace.getSession().getTotalDurationMs();
 
@@ -174,6 +176,32 @@ public class DiagnosisTraceEvaluator {
         return value == null ? null : String.valueOf(value);
     }
 
+    private List<String> validateExecutorStructuredOutput(DiagnosisTraceResponse trace) {
+        Object structuredOutput = nestedValue(trace, "verifier_evaluation", "executor_structured_output");
+        if (!(structuredOutput instanceof Map<?, ?> output)) {
+            return List.of();
+        }
+        Object claims = output.get("claims");
+        if (!(claims instanceof List<?> claimList)) {
+            return List.of("executor structured output missing claims array");
+        }
+
+        List<String> failedChecks = new ArrayList<>();
+        for (Object item : claimList) {
+            if (!(item instanceof Map<?, ?> claim)) {
+                failedChecks.add("executor structured claim is not an object");
+                continue;
+            }
+            Object claimIdValue = claim.get("claim_id");
+            String claimId = claimIdValue == null ? "unknown" : String.valueOf(claimIdValue);
+            Object bindings = claim.get("evidence_bindings");
+            if (!(bindings instanceof List<?> bindingList) || bindingList.isEmpty()) {
+                failedChecks.add("executor confirmed claim missing evidence bindings: " + claimId);
+            }
+        }
+        return failedChecks;
+    }
+
     private Object nestedValue(DiagnosisTraceResponse trace, String firstKey, String secondKey) {
         if (trace.getSession() == null || trace.getSession().getSelfEvaluation() == null) {
             return null;