Generated JVM Groovy projects fail to build

[cdsap]

Summary

Generated JVM projects using Groovy DSL fail during root build script compilation because the generated build.gradle contains Kotlin DSL plugin syntax.

Reproducer

./gradlew :cli:fatBinary
./cli/projectGenerator generate-project \
  --modules 6 \
  --layers 5 \
  --type jvm \
  --language groovy \
  --shape rectangle \
  --output-dir /tmp/pg-jvm-groovy
cd /tmp/pg-jvm-groovy
./gradlew build

Expected behavior

The generated Groovy DSL project builds successfully.

Actual behavior

Gradle rejects the Kotlin DSL kotlin("jvm") call in the generated Groovy plugins block.

Evidence

• JDK: OpenJDK 23.0.2 (Zulu)
• OS: macOS 26.2
• Generator command: ./cli/projectGenerator generate-project --modules 6 --layers 5 --type jvm --language groovy --shape rectangle --output-dir /tmp/pg-jvm-groovy
• Generated project command: ./gradlew build
• Error excerpt:

Build file '/tmp/pg-jvm-groovy/build.gradle' line: 2

only id(String), alias(Provider), or alias(ProviderConvertible) method calls allowed in plugins {} script block

@ line 2, column 5.
    kotlin("jvm") version("2.4.0") apply false
    ^

The root build script is generated by BuildGradle.getJvm, and the same content is currently written for both DSLs.

Scope

Affected area:

• CLI
• YAML parsing
• Core generator
• Android generation
• JVM generation
• Gradle version support
• Documentation
• Tests

Suggested fix or test

Render Groovy-compatible JVM root plugin syntax when the output extension is gradle. Add a focused E2E test that generates a minimal JVM Groovy project and runs ./gradlew build; also cover language=both so both generated variants are built.