migrated to gradle

app/build.gradle.kts

@@ -0,0 +1,21 @@
+plugins {
+    application
+}
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    implementation(project(":lib"))
+}
+
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(24)
+    }
+}
+
+application {
+    mainClass = "demo.Main"
+}