fix: recover WeChat page thumbnail delivery

wechat/image-generation-policy.test.mjs

@@ -7,6 +7,10 @@ import {
   WECHAT_PAGE_THUMBNAIL_MODE,
 } from './image-generation-policy.mjs';
 import { classifyWechatIntent } from './intent/classifier.mjs';
+import {
+  buildPageGenerateAgentPrompt,
+  buildPagePublishFailureText,
+} from './prompts/page-generate.mjs';
 
 test('service-account page always requires a fresh thumbnail without forcing body images', () => {
   const policy = resolveWechatImageGenerationPolicy({
@@ -18,7 +22,11 @@ test('service-account page always requires a fresh thumbnail without forcing bod
   assert.equal(policy.imageGenerationMode, 'required');
   assert.equal(policy.inlineImageMode, 'auto');
   assert.equal(policy.standaloneImageMode, 'auto');
-  assert.match(buildWechatPageImageInstruction(policy), /每个本轮交付给用户的正式内容页面/);
+  const instruction = buildWechatPageImageInstruction(policy);
+  assert.match(instruction, /每个本轮交付给用户的正式内容页面/);
+  assert.match(instruction, /Agent 层只调用一次 generate_image/);
+  assert.match(instruction, /工具内部会完成语义重试/);
+  assert.match(instruction, /禁止自行更换提示词并重复调用/);
 });
 
 test('no-image page request disables body images but keeps required fresh thumbnail', () => {
@@ -62,3 +70,20 @@ test('explicitly declining a page keeps standalone image generation out of page
   assert.equal(policy.pageThumbnailMode, 'auto');
   assert.equal(policy.standaloneImageMode, 'required');
 });
+
+test('page generation prompt forbids unsupported commercial and security claims', () => {
+  const prompt = buildPageGenerateAgentPrompt({
+    agentText: '生成 TKMind 舌战群儒页面',
+    msgId: 'message-1',
+  });
+  assert.match(prompt, /禁止编造用户未提供的产品指标、客户数量、SLA、认证、案例、排名或承诺/);
+  assert.match(prompt, /不得杜撰数字/);
+});
+
+test('missing-thumbnail copy preserves the page and does not ask for the full requirement again', () => {
+  const text = buildPagePublishFailureText({ missingFreshThumbnail: true });
+  assert.match(text, /页面内容已经保留/);
+  assert.match(text, /重试上次页面/);
+  assert.match(text, /无需重新描述完整需求/);
+  assert.doesNotMatch(text, /重发一次完整页面需求/);
+});