Add email verification system for user registration

- Add SMTP configuration UI in admin panel with test functionality
- Implement email verification workflow with tokens and templates
- Add verification success/expired pages for user feedback
- Include nodemailer, handlebars, and JWT dependencies
- Create API endpoints for email config, testing, and verification

utils/types.ts

@@ -189,6 +189,16 @@ export interface RegistrationConfig {
   accountHolder: string;
 }
 
+export interface SMTPConfig {
+  host: string;
+  port: number;
+  secure: boolean;
+  username: string;
+  password: string;
+  fromAddress: string;
+  fromName: string;
+}
+
 // Enhanced Keycloak Admin API Types
 export interface KeycloakUserRepresentation {
   id?: string;