fix(wechat): trust configured imgproxy generated images

wechat-media.test.mjs

@@ -36,3 +36,38 @@ test('uploadWechatGeneratedImage converts a generated asset and uploads WeChat i
   assert.match(calls[1].url, /access_token=access-1/);
   assert.match(calls[1].url, /type=image/);
 });
+
+test('uploadWechatGeneratedImage accepts configured imgproxy origin and rejects unknown origins', async () => {
+  const source = await sharp({
+    create: { width: 16, height: 16, channels: 3, background: '#884422' },
+  }).png().toBuffer();
+  const wechatFetch = async (url) => {
+    if (String(url).startsWith('https://img.example.com/')) {
+      return new Response(source, { status: 200, headers: { 'Content-Type': 'image/png' } });
+    }
+    return new Response(JSON.stringify({ type: 'image', media_id: 'wx-media-imgproxy' }), {
+      status: 200,
+      headers: { 'Content-Type': 'application/json' },
+    });
+  };
+
+  const accepted = await uploadWechatGeneratedImage(
+    'access-2',
+    'https://img.example.com/signed/generated.webp',
+    {
+      publicBaseUrl: 'https://app.example.com',
+      allowedPublicBaseUrls: ['https://img.example.com'],
+      wechatFetch,
+    },
+  );
+  assert.equal(accepted.mediaId, 'wx-media-imgproxy');
+
+  await assert.rejects(
+    uploadWechatGeneratedImage('access-2', 'https://untrusted.example.net/generated.webp', {
+      publicBaseUrl: 'https://app.example.com',
+      allowedPublicBaseUrls: ['https://img.example.com'],
+      wechatFetch,
+    }),
+    /可信公网域名/,
+  );
+});