Implement Two-Factor Authentication (2FA) features and enhancements

- Added configuration options for Two-Factor Authentication, including TOTP encryption key.
- Updated user profile components to manage 2FA status and backup codes.
- Implemented encryption and decryption of TOTP secrets using AES-256-GCM.
- Enhanced backup code generation and validation processes, storing hashed codes securely.
- Introduced new routes and handlers for managing backup codes and 2FA setup.
- Updated README with detailed instructions and security considerations for 2FA implementation.

components/two_factor_verify.templ

@@ -71,11 +71,19 @@ templ TwoFactorVerify(ctx context.Context, data TwoFactorVerifyData) {
 						</button>
 
 						<div class="text-center">
-							<a href="/backup-code" class="text-sm text-primary-600 dark:text-primary-400 hover:text-primary-500 dark:hover:text-primary-300">
+							<a href="/login/backup-code" class="text-sm text-primary-600 dark:text-primary-400 hover:text-primary-500 dark:hover:text-primary-300">
 								Use a backup code instead
 							</a>
 						</div>
 					</form>
+					
+					<div class="mt-6 text-center">
+						<p class="text-sm text-secondary-600 dark:text-secondary-400">
+							Lost your device?
+							<br/>
+							You can use one of your backup codes instead of the 6-digit code.
+						</p>
+					</div>
 				</div>
 			</div>
 		</div>