feat(harness): improve trace fallback and reasoning audit

src/main/java/com/superbiz/agent/harness/application/ChatApplicationUseCase.java

@@ -3,6 +3,8 @@ package com.superbiz.agent.harness.application;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.superbiz.agent.harness.application.persistence.ChatRunStore;
+import com.superbiz.agent.harness.audit.DiagnosisTraceRecorder;
+import com.superbiz.agent.harness.audit.TraceAuditEvents;
 import com.superbiz.agent.harness.application.persistence.RoutingHistory;
 import com.superbiz.agent.harness.application.routing.IntentRouterInput;
 import com.superbiz.agent.harness.application.routing.IntentRoutingException;
@@ -33,6 +35,7 @@ public final class ChatApplicationUseCase {
     private final KnowledgeQueryOperation knowledgeQuery;
     private final DiagnosisOperation diagnosis;
     private final ObjectMapper objectMapper;
+    private final DiagnosisTraceRecorder traceRecorder;
 
     public ChatApplicationUseCase(DiagnosisHarnessCore core,
                                   Supplier<String> sessionIdSupplier,
@@ -42,6 +45,19 @@ public final class ChatApplicationUseCase {
                                   KnowledgeQueryOperation knowledgeQuery,
                                   DiagnosisOperation diagnosis,
                                   ObjectMapper objectMapper) {
+        this(core, sessionIdSupplier, runStore, router, systemChat, knowledgeQuery,
+                diagnosis, objectMapper, DiagnosisTraceRecorder.noop());
+    }
+
+    public ChatApplicationUseCase(DiagnosisHarnessCore core,
+                                  Supplier<String> sessionIdSupplier,
+                                  ChatRunStore runStore,
+                                  IntentRouting router,
+                                  SystemChatOperation systemChat,
+                                  KnowledgeQueryOperation knowledgeQuery,
+                                  DiagnosisOperation diagnosis,
+                                  ObjectMapper objectMapper,
+                                  DiagnosisTraceRecorder traceRecorder) {
         this.core = Objects.requireNonNull(core, "core must not be null");
         this.sessionIdSupplier = Objects.requireNonNull(
                 sessionIdSupplier, "sessionIdSupplier must not be null");
@@ -51,6 +67,7 @@ public final class ChatApplicationUseCase {
         this.knowledgeQuery = Objects.requireNonNull(knowledgeQuery, "knowledgeQuery must not be null");
         this.diagnosis = Objects.requireNonNull(diagnosis, "diagnosis must not be null");
         this.objectMapper = Objects.requireNonNull(objectMapper, "objectMapper must not be null");
+        this.traceRecorder = Objects.requireNonNull(traceRecorder, "traceRecorder must not be null");
     }
 
     public ChatApplicationResult execute(ChatApplicationRequest request) {
@@ -78,12 +95,14 @@ public final class ChatApplicationUseCase {
         IntentType intent = null;
         try {
             persistStart(context, request.query());
+            traceRecorder.record(TraceAuditEvents.runStarted(context));
             observer.onStarted(new CoreRunControl(core, context));
             observer.onStatus(ChatApplicationStatus.ROUTING);
             intent = router.route(context, new IntentRouterInput(
                     request.query(),
                     history.map(RoutingHistory::intent).orElse(null),
                     history.map(RoutingHistory::userQuery).orElse(null)));
+            traceRecorder.record(TraceAuditEvents.routingDecision(context, intent));
             persistIntent(context.runId(), intent);
 
             PathResult path = executePath(
@@ -93,6 +112,8 @@ public final class ChatApplicationUseCase {
             String safeJson = write(path.content());
             persistFinish(context, intent, path.outcome(), safeJson,
                     path.publishedResult(), durationMillis(startedNanos));
+            traceRecorder.record(TraceAuditEvents.runFinished(
+                    context, intent, path.outcome(), durationMillis(startedNanos)));
             return new ChatApplicationResult(
                     context.sessionId(), context.runId(), intent, path.outcome(),
                     path.content().contentType(), path.content());
@@ -104,6 +125,8 @@ public final class ChatApplicationUseCase {
             } catch (RuntimeException persistenceFailure) {
                 exception.addSuppressed(persistenceFailure);
             }
+            traceRecorder.record(TraceAuditEvents.runFinished(
+                    context, intent, terminal, durationMillis(startedNanos)));
             throw safeFailure(exception, terminal);
         }
     }