fix(demo): suppress this-escape compiler warnings in JavaFX panels

Add @SuppressWarnings("this-escape") to constructors that call
getStyleClass().add() or setOnAction() before the object is fully
initialized. This is safe in JavaFX as these methods only register
callbacks without executing them during construction.

Affected classes:
- LogPanel.java (getStyleClass().add)
- PDFViewerPanel.java (getStyleClass().add)
- SemanticRouterPanel.java (setOnAction)
- SettingsPanel.java (setContent)

Author: bsbodden

demos/rag-multimodal/src/main/java/com/redis/vl/demo/rag/ui/LogPanel.java

@@ -34,6 +34,7 @@ public class LogPanel extends BorderPane {
   /**
    * Creates the log panel.
    */
+  @SuppressWarnings("this-escape")
   public LogPanel() {
     getStyleClass().add("log-panel");
 

demos/rag-multimodal/src/main/java/com/redis/vl/demo/rag/ui/PDFViewerPanel.java

@@ -40,6 +40,7 @@ public class PDFViewerPanel extends BorderPane {
   private final StackPane placeholder;
   private final ScrollPane scrollPane;
 
+  @SuppressWarnings("this-escape")
   public PDFViewerPanel() {
     getStyleClass().add("pdf-viewer-panel");
 

demos/rag-multimodal/src/main/java/com/redis/vl/demo/rag/ui/SemanticRouterPanel.java

@@ -88,6 +88,7 @@ public class SemanticRouterPanel extends ScrollPane {
   /**
    * Creates the semantic router panel with sample routes preloaded.
    */
+  @SuppressWarnings("this-escape")
   public SemanticRouterPanel() {
     VBox content = new VBox(12);
     content.setPadding(new Insets(16));

demos/rag-multimodal/src/main/java/com/redis/vl/demo/rag/ui/SettingsPanel.java

@@ -49,6 +49,7 @@ public class SettingsPanel extends ScrollPane {
   /**
    * Creates the settings panel.
    */
+  @SuppressWarnings("this-escape")
   public SettingsPanel() {
     AppConfig config = AppConfig.getInstance();