fix: stop chat hang after misrouted themed article requests

Route themed page/article prompts to agent orchestration, reject them
from portal direct chat, and finalize regular sessions to idle when a
direct chat turn already completed.

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

chat-intent-router.test.mjs

@@ -36,6 +36,19 @@ test('classifyWithRules routes page generation to agent orchestration', () => {
   assert.equal(result.suggestedSkill, 'static-page-publish');
 });
 
+test('classifyWithRules routes themed article requests to agent orchestration', () => {
+  const result = classifyWithRules({
+    text: '帮我写个主题文章',
+    userMessage: {
+      role: 'user',
+      content: [{ type: 'text', text: '帮我写个主题文章' }],
+      metadata: { displayText: '帮我写个主题文章' },
+    },
+  });
+  assert.equal(result.route, CHAT_INTENT_ROUTE.AGENT);
+  assert.equal(result.suggestedSkill, 'static-page-publish');
+});
+
 test('classifyWithRules honors forceDeepReasoning bypass', () => {
   const result = classifyWithRules({
     text: '你好',