enhance build script with progress output and structured asset copying

build.sh

@@ -1,10 +1,24 @@
-rm -rf out/app
+#!/bin/bash
 
-jpackage \
+echo "[1/4] Clearing old files..."
-  --input out/artifacts/JGame2D_jar/ \
+rm -rf "out/app"
-  --main-jar JGame2D.jar \
+
-  --main-class de.miaurizius.jgame2d.core.Boot \
+echo "[2/4] Building game..."
-  --name JGame2D \
+jpackage --type app-image \
-  --type app-image \
+  --dest "out/app" \
-  --add-modules ALL-MODULE-PATH \
+  --name "JGame2D" \
-  --dest out/app
+  --input "out/artifacts/JGame2D_jar" \
+  --main-jar "JGame2D.jar" \
+  --main-class de.miaurizius.jgame2d.core.Boot
+
+echo "[3/4] Copy assets..."
+mkdir -p "out/app/JGame2D/assets"
+cp -r assets/* "out/app/JGame2D/assets/"
+
+echo "[4/4] Zipping..."
+cd out/app
+zip -r ../JGame2D.zip JGame2D
+
+cd ../..
+
+echo "Done!"