fix(chart,dashboardgrid demos): use dees-button text property consistently in demo interactions and update dataset button highlighting reliably

ts_web/elements/00group-chart/dees-chart-log/dees-chart-log.demo.ts

@@ -174,7 +174,7 @@ export const demoFunc = () => {
       // Wire up button click handlers
       const buttons = elementArg.querySelectorAll('dees-button');
       buttons.forEach(button => {
-        const text = button.textContent?.trim();
+        const text = (button as any).text?.trim();
         switch (text) {
           case 'Add Structured Log':
             button.addEventListener('click', () => generateRandomLog());