fix(wechat): enforce current-turn image paths in page delivery

Materialize wechat-mp uploads into dated public/images paths during vision
preprocessing and fail closed when delivered HTML references stale workspace
images instead of the current turn allowlist.

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

wechat/verify/page-artifact.mjs

@@ -1,5 +1,6 @@
 import fs from 'node:fs';
 import path from 'node:path';
+import { verifyHtmlImageSourcesAllowed } from '../../chat-image-materialize.mjs';
 
 const STUB_MARKERS = ['临时补出', '服务号兜底', '服务号自动补出简版页面'];
 
@@ -106,3 +107,36 @@ export function verifyPageArtifactContent(artifact, { minBytes = 512, publishDir
   }
   return { ok: true, reason: null };
 }
+
+export function verifyPageArtifactImageSources(
+  artifact,
+  {
+    publishDir = '',
+    allowedImageEmbedKeys = null,
+  } = {},
+) {
+  const allowed = allowedImageEmbedKeys instanceof Set
+    ? allowedImageEmbedKeys
+    : Array.isArray(allowedImageEmbedKeys)
+      ? new Set(allowedImageEmbedKeys)
+      : null;
+  if (!allowed || allowed.size === 0) {
+    return { ok: true, reason: null, offendingKeys: [] };
+  }
+  const localPath = resolveArtifactLocalPath(artifact, publishDir);
+  if (!localPath) {
+    return { ok: false, reason: 'missing_file', offendingKeys: [] };
+  }
+  let content = '';
+  try {
+    content = fs.readFileSync(localPath, 'utf8');
+  } catch {
+    return { ok: false, reason: 'missing_file', offendingKeys: [] };
+  }
+  const verification = verifyHtmlImageSourcesAllowed(content, allowed);
+  return {
+    ok: verification.ok,
+    reason: verification.reason,
+    offendingKeys: verification.offendingKeys ?? [],
+  };
+}