Add JavaFX menu renderer and player window

- RcoRenderer implements Display: draws the live RCO object tree onto a
  Canvas, decodes PNG textures, handles focus and resource changes
  (thread-safe via Platform.runLater).
- PageObject now implements root/children semantics and open/close/display
  so opening a page adds its objects to the renderer.
- Object getImage() returns the ImageObject so the UI can decode PNGs.
- PlayerApp wires menu + video: loads the RCO, runs the VSMX script,
  executes onAutoPlay, plays video via PlaybackEngine with YUV->ARGB
  blitting and PTS pacing, and routes arrow/Enter keys to the controller.
- Runs end-to-end on Batman Begins (window, menu load, playback).

core/src/main/java/dev/quoije/umd/rco/Display.java

@@ -1,14 +1,16 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 package dev.quoije.umd.rco;
 
+import dev.quoije.umd.rco.vsmx.interpreter.VsmxBaseObject;
+
 /** The rendering surface backing an RCO menu. Implemented by the UI layer. */
 public interface Display {
 
     void setFocus(IDisplay display);
 
-    void add(IDisplay display);
+    void add(VsmxBaseObject object);
 
-    void remove(IDisplay display);
+    void remove(VsmxBaseObject object);
 
     void repaint();
 

core/src/main/java/dev/quoije/umd/rco/object/ButtonObject.java

@@ -26,7 +26,7 @@ public class ButtonObject extends BasePositionObject {
 
     @Override
     public Object getImage() {
-        return image.getImage() == null ? null : image.getImage().getImage();
+        return image.getImage();
     }
 
     @Override

core/src/main/java/dev/quoije/umd/rco/object/IconObject.java

@@ -13,6 +13,6 @@ public class IconObject extends BasePositionObject {
 
     @Override
     public Object getImage() {
-        return unknownImage16.getImage() == null ? null : unknownImage16.getImage().getImage();
+        return unknownImage16.getImage();
     }
 }

core/src/main/java/dev/quoije/umd/rco/object/PageObject.java

@@ -2,9 +2,14 @@
 package dev.quoije.umd.rco.object;
 
 import dev.quoije.umd.rco.ObjectField;
+import dev.quoije.umd.rco.RcoFile;
 import dev.quoije.umd.rco.type.EventType;
 import dev.quoije.umd.rco.type.IntType;
 import dev.quoije.umd.rco.vsmx.interpreter.VsmxBaseObject;
+import dev.quoije.umd.rco.vsmx.interpreter.VsmxInterpreter;
+import dev.quoije.umd.rco.vsmx.interpreter.VsmxNativeObject;
+import dev.quoije.umd.rco.vsmx.interpreter.VsmxObject;
+import dev.quoije.umd.rco.vsmx.objects.Resource;
 
 /** A menu page. */
 public class PageObject extends BaseObject {
@@ -15,8 +20,66 @@ public class PageObject extends BaseObject {
     @ObjectField(order = 4) public EventType onContextMenu;
     @ObjectField(order = 5) public EventType onActivate;
 
+    @Override
+    public VsmxBaseObject createVsmxObject(VsmxInterpreter interpreter, VsmxBaseObject parent, RcoFile.Entry entry) {
+        VsmxBaseObject object = super.createVsmxObject(interpreter, parent, entry);
+        VsmxObject root = new VsmxObject(interpreter, null);
+        object.setPropertyValue(Resource.rootName, root);
+        return root;
+    }
+
+    private void display(VsmxBaseObject object) {
+        if (!object.hasPropertyValue(Resource.childrenName)) {
+            return;
+        }
+        VsmxBaseObject children = object.getPropertyValue(Resource.childrenName);
+        for (String childName : children.getPropertyNames()) {
+            VsmxBaseObject child = children.getPropertyValue(childName);
+            display.add(child);
+            display(child);
+        }
+    }
+
+    private void hide(VsmxBaseObject object) {
+        if (!object.hasPropertyValue(Resource.childrenName)) {
+            return;
+        }
+        VsmxBaseObject children = object.getPropertyValue(Resource.childrenName);
+        for (String childName : children.getPropertyNames()) {
+            VsmxBaseObject child = children.getPropertyValue(childName);
+            display.remove(child);
+            hide(child);
+        }
+    }
+
+    private BasePositionObject getFirstButton(VsmxBaseObject object) {
+        if (!object.hasPropertyValue(Resource.childrenName)) {
+            return null;
+        }
+        VsmxBaseObject children = object.getPropertyValue(Resource.childrenName);
+        for (String childName : children.getPropertyNames()) {
+            VsmxBaseObject child = children.getPropertyValue(childName);
+            if (child instanceof VsmxNativeObject nativeObject && nativeObject.getObject() instanceof UButtonObject button) {
+                return button;
+            }
+            BasePositionObject button = getFirstButton(child);
+            if (button != null) {
+                return button;
+            }
+        }
+        return null;
+    }
+
     public VsmxBaseObject open(VsmxBaseObject object) {
         trigger(onInit);
+
+        if (display != null && object.hasPropertyValue(Resource.rootName)) {
+            display(object.getPropertyValue(Resource.rootName));
+            BasePositionObject button = getFirstButton(object.getPropertyValue(Resource.rootName));
+            if (button != null) {
+                button.setFocus();
+            }
+        }
         return object;
     }
 
@@ -26,6 +89,9 @@ public class PageObject extends BaseObject {
     }
 
     public void close(VsmxBaseObject object) {
+        if (display != null && object.hasPropertyValue(Resource.rootName)) {
+            hide(object.getPropertyValue(Resource.rootName));
+        }
         trigger(onCancel);
     }
 }

core/src/main/java/dev/quoije/umd/rco/object/PlaneObject.java

@@ -13,6 +13,6 @@ public class PlaneObject extends BasePositionObject {
 
     @Override
     public Object getImage() {
-        return image.getImage() == null ? null : image.getImage().getImage();
+        return image.getImage();
     }
 }

core/src/main/java/dev/quoije/umd/rco/object/UButtonObject.java

@@ -21,7 +21,7 @@ public class UButtonObject extends BasePositionObject {
 
     @Override
     public Object getImage() {
-        return image.getImage() == null ? null : image.getImage().getImage();
+        return image.getImage();
     }
 
     @Override