Improve pause info display and error handling

desktop/angular/src/app/layout/navigation/navigation.html

@@ -222,8 +222,8 @@
           <span class="text-secondary">
             <span class="text-secondary">{{ pauseInfo }} </span>
           </span>
-          <span class="text-secondary">
-            Auto-resume at <span class="text-secondary">{{ pauseInfoTillTime }} </span>
+          <span class="text-secondary" *ngIf="pauseInfoTillTime">
+            {{ pauseInfoTillTime }}
           </span>            
         </div>
         <hr/>

desktop/angular/src/app/layout/navigation/navigation.ts

@@ -50,8 +50,12 @@ export class NavigationComponent implements OnInit {
     return '';
   }
   get pauseInfoTillTime(): string {
-    if (this.isPaused && this.pauseState?.TillTime)
-      return new Date(this.pauseState.TillTime).toLocaleTimeString(undefined, { hour12: false });
+    if (this.isPaused && this.pauseState?.TillTime) {
+      const date = new Date(this.pauseState.TillTime);
+      if (isNaN(date.getTime()) || date.getTime() < Date.now())
+        return '';    
+      return `Auto-resume at ${date.toLocaleTimeString(undefined, { hour12: false })}`;
+    }
     return '';
   }