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.
This commit accomplishes a few modifications including the elimination of `use-toast.tsx` due to redundancy. The authentication methods in `personal-accounts-server-actions.ts` were refactored to improve service integration and data handling. Additionally, UI components were updated for better readability and clarity. Cascading deletion was enabled in the `schema.sql` file for 'invited_by' reference.
Added README.md files for several @kit packages including Supabase, UI, Emails, Billing, and Mailers. These documents explain the purpose and usage of each package, facilitating better understanding for developers interacting with them.
