Initial LibGDX project scaffold for ArtLegend

Multi-module Gradle setup targeting Android (S-Pen) and Desktop (Wacom/LWJGL3).
Includes core game stub, Android launcher with immersive mode, and desktop launcher.
Asset directory shared across platforms. Gradle 8.6, Kotlin 1.9.23, LibGDX 1.12.1.

core/build.gradle.kts

@@ -0,0 +1,13 @@
+plugins {
+    kotlin("jvm")
+}
+
+val gdxVersion: String by project
+
+dependencies {
+    api("com.badlogicgames.gdx:gdx:$gdxVersion")
+}
+
+kotlin {
+    jvmToolchain(17)
+}

core/src/main/kotlin/com/artlegend/ArtLegend.kt

@@ -0,0 +1,27 @@
+package com.artlegend
+
+import com.badlogic.gdx.Game
+import com.badlogic.gdx.Gdx
+import com.badlogic.gdx.Screen
+import com.badlogic.gdx.graphics.GL20
+
+class ArtLegend : Game() {
+    override fun create() {
+        setScreen(PlaceholderScreen())
+    }
+}
+
+class PlaceholderScreen : Screen {
+    override fun show() {}
+
+    override fun render(delta: Float) {
+        Gdx.gl.glClearColor(0.08f, 0.08f, 0.10f, 1f)
+        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT)
+    }
+
+    override fun resize(width: Int, height: Int) {}
+    override fun pause() {}
+    override fun resume() {}
+    override fun hide() {}
+    override fun dispose() {}
+}