tweaks and fixes

- introduce kotlin-jvm convention
- tidy up code-quality build config

buildSrc/src/main/kotlin/buildsrc/conventions/lang/kotlin-jvm.gradle.kts

@@ -0,0 +1,42 @@
+package buildsrc.conventions.lang
+
+import buildsrc.utils.Rife2TestListener
+import org.gradle.api.JavaVersion
+import org.gradle.api.tasks.testing.Test
+import org.gradle.api.tasks.testing.logging.TestExceptionFormat
+import org.gradle.api.tasks.testing.logging.TestLogEvent
+import org.gradle.kotlin.dsl.withType
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+import org.jetbrains.kotlin.gradle.targets.jvm.KotlinJvmTarget
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+import org.sonarqube.gradle.SonarTask
+
+/**
+ * Common configuration for Kotlin/JVM projects
+ *
+ * (this can be removed after Kotlin Multiplatform migration)
+ */
+
+plugins {
+    id("buildsrc.conventions.base")
+    kotlin("jvm")
+    id("buildsrc.conventions.code-quality")
+}
+
+java {
+    withSourcesJar()
+}
+
+kotlin {
+    jvmToolchain(11)
+}
+
+tasks.withType<KotlinCompile>().configureEach {
+    compilerOptions {
+        jvmTarget.set(JvmTarget.JVM_11)
+    }
+}
+
+tasks.withType<Test>().configureEach {
+    useJUnitPlatform()
+}