feat(examples): four runnable plugin examples

- player-load: load-on-join (PlayerReadyEvent → IO → modify).
- async-moderation: IAsyncEvent → coroutine bridge for chat moderation.
- periodic-leaderboard: pluginScope loop with parallel reads.
- bounty-board: kitchen-sink demo exercising every v0.1 primitive.

examples/player-load/build.gradle.kts

@@ -0,0 +1,40 @@
+plugins {
+    alias(libs.plugins.kotlin.jvm)
+    alias(libs.plugins.shadow)
+}
+
+group = "com.mythlane.example"
+version = "0.1.0"
+description = "Async example: player-load"
+
+val hytaleServerVersion = libs.versions.hytaleServer.get()
+
+dependencies {
+    compileOnly(libs.hytale.server)
+    implementation("com.mythlane:async:0.1.0-SNAPSHOT")
+}
+
+kotlin {
+    jvmToolchain(25)
+    compilerOptions { jvmTarget.set(org.jetbrains.kotlin.gradle.dsl.JvmTarget.JVM_24) }
+}
+
+tasks.withType<JavaCompile>().configureEach { options.release.set(24) }
+
+tasks.processResources {
+    filteringCharset = Charsets.UTF_8.name()
+    val props = mapOf(
+        "version" to project.version,
+        "description" to (project.description ?: ""),
+        "hytaleServerVersion" to hytaleServerVersion,
+    )
+    inputs.properties(props)
+    filesMatching("manifest.json") { expand(props) }
+}
+
+tasks.shadowJar {
+    archiveBaseName.set(project.name)
+    archiveClassifier.set("")
+}
+tasks.jar { enabled = false }
+tasks.build { dependsOn(tasks.shadowJar) }