fix(macos): focus existing window on dock reopen + skin font NPE

lightcrafts/src/main/java/com/lightcrafts/app/Application.java

@@ -174,8 +174,19 @@ public static void openFrom(File file, OtherApplication otherApp) {
 
     public static void reOpen(ComboFrame frame) {
         if (frame == null) {
+            // macOS dock-icon reopen: focus most-recently-active frame instead of spawning a duplicate.
+            ComboFrame existing = getActiveFrame();
+            if (existing != null) {
+                if (existing.getState() == Frame.ICONIFIED) {
+                    existing.setState(Frame.NORMAL);
+                }
+                existing.setVisible(true);
+                existing.toFront();
+                existing.requestFocus();
+                return;
+            }
             openEmpty();
-	    return;
+            return;
         }
         Document doc = frame.getDocument();
         File file = doc.getFile();

lightcrafts/src/main/java/com/lightcrafts/ui/LightZoneSkin.java

@@ -69,9 +69,9 @@ private static Color relight(Color color, float amount) {
     }
 
     public static class LightZoneFontSet {
-        // cf. https://www.formdev.com/flatlaf/typography/#available
-        public static final FontUIResource TitleFont = new FontUIResource(UIManager.getFont("small.font"));
-        public static final FontUIResource SmallFont = new FontUIResource(UIManager.getFont("small.font"));
+        // FlatLaf "small.font" key is not present in every theme variant; hardcode to avoid NPE.
+        public static final FontUIResource TitleFont = new FontUIResource(new Font(Font.SANS_SERIF, Font.PLAIN, 11));
+        public static final FontUIResource SmallFont = new FontUIResource(new Font(Font.SANS_SERIF, Font.PLAIN, 11));
     }
 
     public static Border getImageBorder() {

macosx/build.gradle.kts

@@ -12,6 +12,10 @@ dependencies {
 }
 application {
     mainClass.set("com.lightcrafts.platform.macosx.MacOSXLauncher")
+    applicationDefaultJvmArgs = applicationDefaultJvmArgs + listOf(
+        "-Xdock:name=LightZone",
+        "-Dapple.awt.application.name=LightZone",
+    )
 }
 tasks {
     build {
@@ -86,6 +90,7 @@ runtime {
             "-Djava.library.path=\$APPDIR",
             "-Dfile.encoding=utf-8",
             "-Xdock:name=LightZone",
+            "-Dapple.awt.application.name=LightZone",
         )
     }
 }