Harden evidence trace semantics

src/test/java/com/superbiz/agent/service/ChatServiceSequentialAgentTest.java

@@ -24,6 +24,7 @@ import java.util.Optional;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertSame;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
@@ -85,6 +86,73 @@ class ChatServiceSequentialAgentTest {
         assertEquals(List.of("chat_planner", "chat_executor", "chat_verifier"), chatModel.agentCalls);
     }
 
+    @Test
+    void executeChatComplexFallsBackToLowConfidenceWhenVerifierOutputMissing() throws Exception {
+        ChatService chatService = createChatService();
+        ScriptedChatModel chatModel = new ScriptedChatModel("", "");
+
+        ChatService.ChatResult result = chatService.executeChatComplex(
+                chatModel,
+                new ToolCallback[0],
+                "请分析订单支付超时的原因，并给出修复建议",
+                List.of(),
+                "sequential-missing-verifier-session"
+        );
+
+        assertTrue(result.answer().startsWith("以下结论基于当前已获取证据"));
+        assertEquals(List.of("chat_planner", "chat_executor", "chat_verifier", "chat_verifier"), chatModel.agentCalls);
+    }
+
+    @Test
+    void executeChatComplexFallsBackToLowConfidenceWhenVerifierJsonInvalid() throws Exception {
+        ChatService chatService = createChatService();
+        ScriptedChatModel chatModel = new ScriptedChatModel("not-json");
+
+        ChatService.ChatResult result = chatService.executeChatComplex(
+                chatModel,
+                new ToolCallback[0],
+                "请分析订单支付超时的原因，并给出修复建议",
+                List.of(),
+                "sequential-invalid-verifier-session"
+        );
+
+        assertTrue(result.answer().startsWith("以下结论基于当前已获取证据"));
+        assertEquals(List.of("chat_planner", "chat_executor", "chat_verifier"), chatModel.agentCalls);
+    }
+
+    @Test
+    void executeChatComplexRejectOutputDoesNotLeakExecutorAnswer() throws Exception {
+        ChatService chatService = createChatService();
+        ScriptedChatModel chatModel = new ScriptedChatModel("""
+                {
+                  "verdict": "REJECT",
+                  "groundedness_score": 0.0,
+                  "critical_fact_count": 1,
+                  "facts_checked": [
+                    {
+                      "fact": "payment timeout root cause",
+                      "is_critical": true,
+                      "verification": "contradicted",
+                      "detail": "scripted contradiction",
+                      "evidence_refs": []
+                    }
+                  ],
+                  "rationale": "scripted reject"
+                }
+                """);
+
+        ChatService.ChatResult result = chatService.executeChatComplex(
+                chatModel,
+                new ToolCallback[0],
+                "请分析订单支付超时的原因，并给出修复建议",
+                List.of(),
+                "sequential-reject-session"
+        );
+
+        assertTrue(result.answer().startsWith("当前无法基于已获取证据生成可靠结论"));
+        assertFalse(result.answer().contains("EXECUTOR_FINAL_ANSWER"));
+    }
+
     @Test
     void executeChatComplexRunsPlannerExecutorVerifierInFixedOrder() throws Exception {
         ChatService chatService = createChatService();
@@ -174,7 +242,8 @@ class ChatServiceSequentialAgentTest {
         private final java.util.ArrayList<String> agentCalls = new java.util.ArrayList<>();
         private String promptText = "";
         private boolean sawVerifierPrompt;
-        private final String verifierOutput;
+        private final java.util.List<String> verifierOutputs;
+        private int verifierOutputIndex;
 
         private ScriptedChatModel() {
             this("""
@@ -197,7 +266,11 @@ class ChatServiceSequentialAgentTest {
         }
 
         private ScriptedChatModel(String verifierOutput) {
-            this.verifierOutput = verifierOutput;
+            this.verifierOutputs = java.util.List.of(verifierOutput);
+        }
+
+        private ScriptedChatModel(String... verifierOutputs) {
+            this.verifierOutputs = java.util.List.of(verifierOutputs);
         }
 
         @Override
@@ -213,7 +286,9 @@ class ChatServiceSequentialAgentTest {
             } else if (promptText.contains("VERIFIER_TEST_PROMPT")) {
                 agentCalls.add("chat_verifier");
                 sawVerifierPrompt = true;
-                text = verifierOutput;
+                int index = Math.min(verifierOutputIndex, verifierOutputs.size() - 1);
+                text = verifierOutputs.get(index);
+                verifierOutputIndex++;
             } else {
                 text = "UNEXPECTED_PROMPT";
             }