fix(wiki): proxy topology through public gateway

Co-Authored-By: OpenAI Codex <codex@openai.com>

data/wiki/guanghan_topology_demo.html

@@ -128,7 +128,9 @@
 </div>
 
 <script>
-const API_BASE = '';
+// Keep API calls beside the HTML document so the app works both at the
+// service root and behind a reverse-proxy prefix such as /topology/.
+const API_BASE = new URL('.', window.location.href).pathname.replace(/\/$/, '');
 const SVG_NS = 'http://www.w3.org/2000/svg';
 const TYPE_LABELS = { module: '舱段模块', node: '结构节点', vehicle: '着陆器/车辆', equipment: '设备模块' };
 const ANCHOR_LABELS = {