fix: getBaseUrl() returns correct module prefix for /dashboard_for_sage path

wwwroot/dashboard_refresh.js

@@ -9,9 +9,9 @@
     // Derive base URL from current page (e.g. /dashboard_for_sage/index.ui -> /dashboard_for_sage)
     function getBaseUrl() {
         var path = window.location.pathname;
-        // Remove .ui or .dspy extension
-        var idx = path.lastIndexOf('/');
-        return path.substring(0, idx);
+        // path is like /dashboard_for_sage/index.ui or /dashboard_for_sage
+        var parts = path.split('/').filter(function(p) { return p; });
+        return '/' + parts[0];
     }
 
     function buildUrl(dspyFile) {