The commit adds detailed error messages for missing environment variables across different configuration files. It updates the zod schema validations in different files, such as feature-flags.config.ts, personal-accounts-server-actions.ts, and others to provide more informative error messages when environment variables are not provided.
This commit refactors how SMTP configuration for mailers is set up and introduces schema validation for incoming configurations. The mailer modules have been restructured, with schema definition files added, and redundant codes removed. Moreover, web application configuration now has minimum validation on name and title, and URL validation has been added.
