feat: generate docker-compose.yaml during dry-run mode

[GAlexeyV]

Issue to address: #231

Summary

The --dry-run flag now generates the docker-compose.yaml file in the output folder, allowing users to inspect the Docker configuration without starting services.

Changes

• Added GenerateDockerComposeFile() method to LocalRunner for independent docker-compose generation
• Added skipImageValidation flag to skip Docker daemon checks during dry-run
• Moved docker-compose generation before dry-run exit in main.go
• Removed duplicate generation from Run() method

Testing

• Verified with ./builder-playground start l1 --dry-run
• Verified with ./builder-playground start opstack --dry-run
• All unit tests pass (except Docker-dependent integration test)

[metachris]

please no AI generated bounty farming

[GAlexeyV]

please no AI generated bounty farming

@metachris hi,

Thank you for reviewing
Is implementation wrong or you do not accept contributions even if they correct but AI generated?
I reviewed and tested AI generated code