feat: add Micronaut Kotlin example

with-micronaut-kotlin/.gitignore

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+# Gradle
+.gradle/
+build/
+
+# IntelliJ IDEA
+.idea/
+*.iml
+*.iws
+*.ipr
+out/
+
+# VS Code
+.vscode/
+
+# Environment variables
+.env
+
+# Logs
+*.log
+
+# Compiled class files
+*.class
+
+# Package files
+*.jar
+*.war
+*.ear
+*.zip
+*.tar.gz
+*.rar
+
+# Micronaut
+.micronaut/

with-micronaut-kotlin/README.md

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+# Micronaut Kotlin with Neon Postgres
+
+This example demonstrates how to connect a Micronaut Kotlin application to a Neon Postgres database.
+
+## Prerequisites
+
+- [JDK 11+](https://www.oracle.com/java/technologies/javase-downloads.html)
+- [Gradle](https://gradle.org/install/) (or use the included Gradle wrapper)
+- [Neon account](https://neon.tech)
+
+## Setup
+
+1. Create a Neon project from the [Neon Console](https://console.neon.tech)
+2. Get your connection string from the Neon Console
+3. Create a `.env` file in the project root with your Neon credentials:
+
+```
+JDBC_DATABASE_URL=jdbc:postgresql://<user>:<password>@<endpoint_hostname>.neon.tech:<port>/<dbname>?sslmode=require
+JDBC_DATABASE_USERNAME=<user>
+JDBC_DATABASE_PASSWORD=<password>
+```
+
+## Running the application
+
+```bash
+# Using the Gradle wrapper
+./gradlew run
+```
+
+The application will start on port 8080. You can test it with:
+
+```bash
+# Get all books
+curl http://localhost:8080/books
+
+# Get a specific book
+curl http://localhost:8080/books/1
+
+# Create a new book
+curl -X POST -H "Content-Type: application/json" -d '{"title":"The Great Gatsby","author":"F. Scott Fitzgerald"}' http://localhost:8080/books
+```
+
+## Project Structure
+
+- `src/main/kotlin/com/example/entity/Book.kt` - Entity class representing a book
+- `src/main/kotlin/com/example/repository/BookRepository.kt` - Repository interface for database operations
+- `src/main/kotlin/com/example/controller/BookController.kt` - REST controller for the API
+- `src/main/resources/application.yml` - Application configuration including database connection
+- `src/main/resources/db/migration/V1__create_book_table.sql` - Database migration script
+
+## Learn More
+
+- [Neon Documentation](https://neon.tech/docs)
+- [Micronaut Documentation](https://micronaut.io/documentation/)

with-micronaut-kotlin/build.gradle.kts

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+plugins {
+    id("org.jetbrains.kotlin.jvm") version "1.9.22"
+    id("org.jetbrains.kotlin.plugin.allopen") version "1.9.22"
+    id("org.jetbrains.kotlin.kapt") version "1.9.22"
+    id("com.github.johnrengelman.shadow") version "8.1.1"
+    id("io.micronaut.application") version "4.3.2"
+}
+
+version = "0.1"
+group = "com.example"
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    // Kotlin
+    implementation("io.micronaut.kotlin:micronaut-kotlin-runtime")
+    implementation("org.jetbrains.kotlin:kotlin-reflect")
+    implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
+
+    // Micronaut
+    implementation("io.micronaut:micronaut-http-client")
+    implementation("io.micronaut:micronaut-jackson-databind")
+
+    // Database
+    implementation("io.micronaut.sql:micronaut-jdbc-hikari")
+    implementation("io.micronaut.data:micronaut-data-jdbc")
+    implementation("org.postgresql:postgresql")
+    implementation("io.micronaut.flyway:micronaut-flyway")
+
+    // Logging
+    runtimeOnly("ch.qos.logback:logback-classic")
+
+    // Testing
+    testImplementation("io.micronaut.test:micronaut-test-junit5")
+    testImplementation("org.junit.jupiter:junit-jupiter-api")
+    testImplementation("org.junit.jupiter:junit-jupiter-engine")
+}
+
+application {
+    mainClass.set("com.example.ApplicationKt")
+}
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_17
+    targetCompatibility = JavaVersion.VERSION_17
+}
+
+tasks {
+    compileKotlin {
+        kotlinOptions {
+            jvmTarget = "17"
+            javaParameters = true
+        }
+    }
+    compileTestKotlin {
+        kotlinOptions {
+            jvmTarget = "17"
+            javaParameters = true
+        }
+    }
+}
+
+micronaut {
+    version("4.2.0")
+    runtime("netty")
+    testRuntime("junit5")
+    processing {
+        incremental(true)
+        annotations("com.example.*")
+    }
+}

with-micronaut-kotlin/gradle/wrapper/gradle-wrapper.properties

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+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists