Generate a Spring Boot Kotlin project skeleton with pre-configured databases and development services.

• Downloads a Spring Boot 3.4.5 project template with Kotlin, WebFlux, R2DBC, Redis, and MongoDB dependencies via Spring Initializr
• Includes Docker Compose configuration for PostgreSQL 17, Redis 6, and MongoDB 8 with pre-set credentials and volume mounts
• Adds SpringDoc OpenAPI integration for Swagger UI documentation and ArchUnit for architecture testing
• Requires Java 21, Docker, and Docker Compose; customizable project name, Spring Boot version, and package structure through template variables