feat: enhance sign-up process with email verification flow and error handling. Introduce new toast messages for verification success and continuation, and implement duplicate email error detection. Update sign-up form to streamline user experience and improve feedback during the verification process.
feat: enhance testing capabilities and introduce new components for question management. Add testing section in AGENTS.md with instructions for running tests and configuring the test environment. Update package.json files to include test scripts and integrate @electric-sql/pglite for in-memory database testing. Introduce CalloutCard and update FilterBar and SoalBrowser components to support visibility filters for private and public questions. Implement new test cases for various functionalities across the application.
