feat(cli): enable backend.kotlin and backend.groovy templates

[marioserrano09]

Part of #91.

Enables template.backend.kotlin and template.backend.groovy in cli.properties now that both templates
have real, verified scaffolds:

• https://github.com/dynamiatools/template-backend-kotlin (commit 9dbe2c0)
• https://github.com/dynamiatools/template-backend-groovy (commit 59b3991)

Both mirror template-backend-java's dependency set and structure, and include a fix for
#102 (ModuleContainer needs a non-empty
List<ModuleProvider> at startup — also backported to template-backend-java).

Verification

Ran the actual CLI end-to-end for all three backend languages, then built each generated project:

dynamia new --name smoke-kotlin --scaffold backend --backend-lang kotlin --yes --no-git
cd smoke-kotlin/backend && ./mvnw clean verify   # BUILD SUCCESS, 1 test run, 0 failures

dynamia new --name smoke-groovy --scaffold backend --backend-lang groovy --yes --no-git
cd smoke-groovy/backend && ./mvnw clean verify   # BUILD SUCCESS, 1 test run, 0 failures

dynamia new --name smoke-java2 --scaffold backend --backend-lang java --yes --no-git
cd smoke-java2/backend && ./mvnw clean verify    # BUILD SUCCESS, 1 test run, 0 failures

frontend.vue/frontend.react remain disabled — their scaffolds are still pending (#91).

🤖 Generated with Claude Code

https://claude.ai/code/session_01UcARdenC1Sk5EVpkzboH9W