more build improvements

plt-build/build.gradle.kts

@@ -1,5 +1,6 @@
 plugins {
-    id("java")
+    kotlin("jvm") version "2.2.10"
+    kotlin("plugin.serialization") version "2.2.20"
 }
 
 group = "moe.rosa"
@@ -13,8 +14,17 @@ dependencies {
     testImplementation(platform("org.junit:junit-bom:5.10.0"))
     testImplementation("org.junit.jupiter:junit-jupiter")
     testRuntimeOnly("org.junit.platform:junit-platform-launcher")
+
+    testImplementation(kotlin("test"))
+    implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.9.0")
+    implementation(kotlin("reflect"))
+}
+
+kotlin {
+    jvmToolchain(24)
 }
 
 tasks.test {
     useJUnitPlatform()
-}
+}
+project.layout.buildDirectory.set(file("../build"))

plt-build/settings.gradle.kts

@@ -0,0 +1 @@
+rootProject.name = "plt-build"