refactor: extract core-model into its own module

core-model/build.gradle.kts

@@ -0,0 +1,13 @@
+plugins {
+    id("java-library")
+    alias(libs.plugins.kotlin.jvm)
+}
+java {
+    sourceCompatibility = JavaVersion.VERSION_11
+    targetCompatibility = JavaVersion.VERSION_11
+}
+kotlin {
+    compilerOptions {
+        jvmTarget = org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_11
+    }
+}