feat(agent): add executor evidence v2 contract

src/test/java/com/superbiz/agent/hook/VerifierInputHookTest.java

@@ -84,6 +84,55 @@ class VerifierInputHookTest {
         assertEquals("valid", VerifierContextHolder.getExecutorOutputParseStatus().get("status"));
     }
 
+    @Test
+    void beforeModelAddsStructuredExecutorOutputWhenV2ContractHasNoUserFacingAnswer() throws Exception {
+        ToolTraceSummaryService traceSummaryService = mock(ToolTraceSummaryService.class);
+        when(traceSummaryService.buildVerifierTraceSummary(anyString(), anyString())).thenReturn(List.of(
+                Map.of("trace_ref", "trace-1", "tool_name", "query_metrics")
+        ));
+        VerifierInputHook hook = new VerifierInputHook(traceSummaryService);
+        VerifierContextHolder.setOriginalQuery("分析 MySQL 连接池耗尽");
+
+        String executorOutput = """
+                {
+                  "answer_version": "executor_evidence_v2",
+                  "claims": [
+                    {
+                      "claim_id": "claim-1",
+                      "claim_type": "symptom",
+                      "claim_text": "连接池 active 达到上限",
+                      "support_level": "direct",
+                      "evidence_bindings": [
+                        {
+                          "source_type": "tool_trace",
+                          "source_id": "trace-1",
+                          "tool_name": "query_metrics",
+                          "source_invocation_ids": [101],
+                          "evidence_excerpt": "active=50 max=50"
+                        }
+                      ]
+                    }
+                  ],
+                  "hypotheses": [],
+                  "recommended_actions": [],
+                  "missing_info": []
+                }
+                """;
+
+        AgentCommand command = hook.beforeModel(
+                List.of(new AssistantMessage(executorOutput)),
+                RunnableConfig.builder().addMetadata("sessionId", "structured-v2-session").build()
+        );
+
+        JsonNode payload = readPayload(command);
+        assertEquals("valid", payload.path("executor_output_parse_status").path("status").asText());
+        assertEquals("executor_evidence_v2",
+                payload.path("executor_structured_output").path("answer_version").asText());
+        assertFalse(payload.path("executor_structured_output").has("user_facing_answer"));
+        assertEquals("连接池 active 达到上限",
+                payload.path("executor_structured_output").path("claims").get(0).path("claim_text").asText());
+    }
+
     @Test
     void beforeModelExtractsStructuredOutputFromPrefixedJsonFence() throws Exception {
         ToolTraceSummaryService traceSummaryService = mock(ToolTraceSummaryService.class);