fix: health chip API_BASE scope (use App.apiBase)

payload/user/remote_access/pager-webui/www/js/app.js

@@ -495,7 +495,7 @@ const Live = (() => {
     if (el) el.textContent = 'BAT ' + (b.level == null ? '--' : b.level + '%' + (b.charging ? '+' : '')) + '  CLIENTS ' + n;
   }
   function pollHealth() {
-    fetch(API_BASE + '/api/health', { credentials: 'include' }).then((r) => r.json())
+    fetch(App.apiBase + '/api/health', { credentials: 'include' }).then((r) => r.json())
       .then((h) => {
         const el = document.getElementById('health-status');
         if (!el) return;