This commit replaces the previous use of execSync to generate .env.local files with the use of writeFileSync. It also updates the corresponding path and default value in the validation process. This change provides a more efficient and safer way to create these files and correctly update the related prompts.
Added a new generator for creating environment variables and a validator to check the validity of the created variables. Also updated the config file to include these new generators in the list of registered generators.
