feat: add episodic history recall

chat-intent-router.test.mjs

@@ -743,6 +743,13 @@ test('classifyWithRules routes memory recall to direct chat on fresh session', (
   });
   assert.equal(result.route, CHAT_INTENT_ROUTE.DIRECT_CHAT);
   assert.match(result.reason, /记忆/);
+
+  const lastConversation = classifyWithRules({
+    text: '上次我们聊了什么？',
+    sessionId: '20260704_4',
+    sessionMessageCount: 0,
+  });
+  assert.equal(lastConversation.route, CHAT_INTENT_ROUTE.DIRECT_CHAT);
 });
 
 test('createChatIntentRouter fast-paths news lookup to agent without LLM', async () => {
@@ -1182,6 +1189,53 @@ test('agent memory canary injects only for configured user ids', async () => {
   assert.equal(control.memories.length, 1);
 });
 
+test('agent memory recall prioritizes historical session evidence over personal memory', async () => {
+  const episodicCalls = [];
+  const router = createChatIntentRouter({
+    env: {
+      MEMORY_AGENT_RESOLVE_ENABLED: '1',
+      MEMORY_AGENT_INJECTION_MODE: 'active',
+      MEMORY_AGENT_RESOLVE_LIMIT: '3',
+      MEMORY_AGENT_RESOLVE_TIMEOUT_MS: '200',
+    },
+    memoryV2: {
+      async resolve() {
+        return {
+          source: 'pgvector',
+          memories: [{ id: 'personal-1', label: '偏好', text: '用户喜欢历史话题' }],
+        };
+      },
+    },
+    episodicMemoryService: {
+      async resolve(input) {
+        episodicCalls.push(input);
+        return {
+          source: 'episodic-index',
+          memories: [{
+            id: 'episodic:old-session',
+            label: '历史会话',
+            text: '会话“日本战国史”：用户与助手讨论过德川家康。',
+          }],
+        };
+      },
+    },
+  });
+
+  const result = await router.resolveAgentMemoryContext({
+    userId: 'user-1',
+    sessionId: 'current-session',
+    text: '我们之前聊过德川家康，你还记得吗？',
+  });
+
+  assert.equal(result.skipped, false);
+  assert.equal(result.injectionEnabled, true);
+  assert.equal(result.source, 'episodic+personal');
+  assert.equal(result.memories[0].id, 'episodic:old-session');
+  assert.equal(result.memories[1].id, 'personal-1');
+  assert.equal(episodicCalls.length, 1);
+  assert.equal(episodicCalls[0].sessionId, 'current-session');
+});
+
 test('active agent memory context is hidden from displayText but available to orchestration envelope', () => {
   const enriched = applyAgentOrchestrationToUserMessage(
     {