fix: [DEFAULT_DIR] resolves to JPATH_ROOT/backups, shown as placeholder

- getDefaultAbsolute() now returns JPATH_ROOT/backups instead of
  the old admin component directory
- SQL default, form default, and install migration all use [DEFAULT_DIR]
- portablize() converts ./backups and old literal paths back to [DEFAULT_DIR]
- Users see [DEFAULT_DIR] in the field, resolved path shown in status

source/script.php

@@ -233,11 +233,12 @@ class Pkg_MokoSuiteBackupInstallerScript
 	{
 		try {
 			$db    = Factory::getDbo();
-			// Check for profiles using the old in-webroot default
+			// Check for profiles using old literal defaults — migrate to [DEFAULT_DIR]
 			$oldDefaults = [
 				'administrator/components/com_mokosuitebackup/backups',
 				'administrator/components/com_mokojoombackup/backups',
-				'[DEFAULT_DIR]',
+				'./backups',
+				'backups',
 			];
 			$query = $db->getQuery(true)
 				->select('COUNT(*)')
@@ -250,10 +251,10 @@ class Pkg_MokoSuiteBackupInstallerScript
 			$db->setQuery($query);
 
 			if ((int) $db->loadResult() > 0) {
-				// Auto-migrate old defaults to the new ./backups convention
+				// Auto-migrate old defaults to [DEFAULT_DIR] placeholder
 				$update = $db->getQuery(true)
 					->update($db->quoteName('#__mokosuitebackup_profiles'))
-					->set($db->quoteName('backup_dir') . ' = ' . $db->quote('./backups'))
+					->set($db->quoteName('backup_dir') . ' = ' . $db->quote('[DEFAULT_DIR]'))
 					->where('(' . $db->quoteName('backup_dir') . ' IN ('
 						. implode(',', array_map([$db, 'quote'], $oldDefaults))
 						. ') OR ' . $db->quoteName('backup_dir') . ' = ' . $db->quote('')