feat: LLM intent router, direct chat execution, and Memory V2 light intervention

Wire chat intent routing with direct_chat on regular sessions, skill-selected
short-circuit to Agent, memory light/heavy intervention tiers, and fix direct
chat UI stuck streaming after completion.

Co-authored-by: Cursor <cursoragent@cursor.com>

conversation-memory.test.mjs

@@ -152,14 +152,16 @@ test('saveAndAnalyze stores messages and fallback memories', async () => {
   else process.env.USER_CONVERSATION_MEMORY_LLM_ENABLED = previous;
 });
 
-test('saveAndAnalyze leaves messages unanalyzed when extraction fails and no memory is stored', async () => {
+test('saveAndAnalyze marks messages analyzed when llm extraction fails and no memory is stored', async () => {
   const previous = process.env.USER_CONVERSATION_MEMORY_LLM_ENABLED;
   process.env.USER_CONVERSATION_MEMORY_LLM_ENABLED = '1';
   const pool = createPool();
   const service = createConversationMemoryService(pool, {
     now: () => 2000,
-    fetch: async () => {
-      throw new Error('upstream unavailable');
+    llmProviderService: {
+      async createChatCompletion() {
+        throw new Error('upstream unavailable');
+      },
     },
   });
 
@@ -174,7 +176,83 @@ test('saveAndAnalyze leaves messages unanalyzed when extraction fails and no mem
 
   assert.equal(result.saved, 1);
   assert.equal(result.memories, 0);
-  assert.equal(pool.state.messages.find((item) => item.message_key === 'm3')?.analyzed_at, null);
+  assert.equal(pool.state.messages.find((item) => item.message_key === 'm3')?.analyzed_at, 2000);
+
+  if (previous == null) delete process.env.USER_CONVERSATION_MEMORY_LLM_ENABLED;
+  else process.env.USER_CONVERSATION_MEMORY_LLM_ENABLED = previous;
+});
+
+test('saveAndAnalyze uses admin effective env for memory extraction model', async () => {
+  const previous = process.env.USER_CONVERSATION_MEMORY_LLM_ENABLED;
+  process.env.USER_CONVERSATION_MEMORY_LLM_ENABLED = '1';
+  const pool = createPool();
+  const llmCalls = [];
+  const service = createConversationMemoryService(pool, {
+    now: () => 2600,
+    getEffectiveEnv: async () => ({
+      MEMIND_CHAT_ROUTER_MODEL_PROVIDER_KEY_ID: 'router-key',
+      MEMIND_CHAT_ROUTER_MODEL: 'deepseek-chat',
+    }),
+    llmProviderService: {
+      async createChatCompletion({ providerKeyId, model, messages }) {
+        llmCalls.push({ providerKeyId, model, messages });
+        return {
+          ok: true,
+          reply: JSON.stringify({
+            memories: [{ label: 'fact', text: '用户叫 John', confidence: 0.9 }],
+          }),
+        };
+      },
+    },
+  });
+
+  await service.saveAndAnalyze('session-admin', 'user-admin', [
+    {
+      id: 'm-admin',
+      role: 'user',
+      content: [{ type: 'text', text: '我是 John。' }],
+    },
+  ]);
+
+  assert.equal(llmCalls.length, 1);
+  assert.equal(llmCalls[0].providerKeyId, 'router-key');
+  assert.equal(llmCalls[0].model, 'deepseek-chat');
+
+  if (previous == null) delete process.env.USER_CONVERSATION_MEMORY_LLM_ENABLED;
+  else process.env.USER_CONVERSATION_MEMORY_LLM_ENABLED = previous;
+});
+
+test('saveAndAnalyze extracts memories through llmProviderService', async () => {
+  const previous = process.env.USER_CONVERSATION_MEMORY_LLM_ENABLED;
+  process.env.USER_CONVERSATION_MEMORY_LLM_ENABLED = '1';
+  const pool = createPool();
+  const service = createConversationMemoryService(pool, {
+    now: () => 2500,
+    llmProviderService: {
+      async createChatCompletion({ messages }) {
+        assert.match(String(messages?.[0]?.content ?? ''), /长期记忆/);
+        return {
+          ok: true,
+          reply: JSON.stringify({
+            memories: [{ label: 'goal', text: '用户计划去日本旅游', confidence: 0.82 }],
+          }),
+        };
+      },
+    },
+  });
+
+  const result = await service.saveAndAnalyze('session-llm', 'user-llm', [
+    {
+      id: 'm-japan',
+      role: 'user',
+      content: [{ type: 'text', text: '我打算带家人去日本玩 5 天。' }],
+      metadata: { userVisible: true },
+    },
+  ]);
+
+  assert.equal(result.memories, 1);
+  assert.equal(pool.state.memories[0].label, 'goal');
+  assert.match(pool.state.memories[0].memory_text, /日本/);
 
   if (previous == null) delete process.env.USER_CONVERSATION_MEMORY_LLM_ENABLED;
   else process.env.USER_CONVERSATION_MEMORY_LLM_ENABLED = previous;