fix(factory): Use same-origin API calls for HAProxy compatibility

Change API base URL to use relative /factory/ path instead of
absolute URL with port 7331. HAProxy routes /factory/* API paths
to the factory backend while serving UI from luci backend.

This fixes mixed content blocking when accessing via HTTPS.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package/secubox/secubox-p2p/root/www/factory/index.html

@@ -140,10 +140,8 @@
     let tools = [];
     let refreshInterval = null;
 
-    // API helpers - API runs on port 7331
-    const apiBase = window.location.port === '7331'
-        ? '/factory/'
-        : 'http://' + window.location.hostname + ':7331/factory/';
+    // API helpers - use same origin (HAProxy routes /factory/* to API)
+    const apiBase = '/factory/';
 
     const api = {
         get: async (path) => {