feat: add post-install verification to detect failed sub-extensions

Checks that all expected component and plugins registered in
#__extensions after install. Disables the package entry and shows
an error if any sub-extension failed to install.

Claude-Session: https://claude.ai/code/session_01CwLGvFJPjoPTp9BEnSjtJf

source/script.php

@@ -17,11 +17,100 @@ use Joomla\CMS\Log\Log;
  */
 class Pkg_MokoSuiteConstructionInstallerScript
 {
+	private const EXPECTED_EXTENSIONS = [
+		['type' => 'component', 'element' => 'com_mokosuiteconstruction'],
+		['type' => 'plugin', 'element' => 'mokosuiteconstruction', 'folder' => 'system'],
+		['type' => 'plugin', 'element' => 'mokosuiteconstruction', 'folder' => 'webservices'],
+	];
+
+	private const PACKAGE_ELEMENT = 'pkg_mokosuiteconstruction';
+	private const PACKAGE_LABEL   = 'MokoSuite Construction';
+
 	public function postflight(string $type, InstallerAdapter $adapter): void
 	{
+		if ($type === 'install')
+		{
+			$missing = $this->verifyInstallation();
+
+			if (!empty($missing))
+			{
+				Factory::getApplication()->enqueueMessage(
+					'<strong>' . self::PACKAGE_LABEL . ' — Incomplete Installation</strong><br>'
+					. 'The following extensions failed to install: '
+					. implode(', ', $missing)
+					. '.<br>Please check file permissions and server logs, then reinstall the package.',
+					'error'
+				);
+				$this->setPackageEnabled(false);
+
+				return;
+			}
+		}
+
 		$this->warnMissingLicenseKey();
 	}
 
+	private function verifyInstallation(): array
+	{
+		$missing = [];
+
+		try
+		{
+			$db = Factory::getDbo();
+
+			foreach (self::EXPECTED_EXTENSIONS as $ext)
+			{
+				$query = $db->getQuery(true)
+					->select('COUNT(*)')
+					->from($db->quoteName('#__extensions'))
+					->where($db->quoteName('type') . ' = ' . $db->quote($ext['type']))
+					->where($db->quoteName('element') . ' = ' . $db->quote($ext['element']));
+
+				if (isset($ext['folder']))
+				{
+					$query->where($db->quoteName('folder') . ' = ' . $db->quote($ext['folder']));
+				}
+
+				$db->setQuery($query);
+
+				if ((int) $db->loadResult() === 0)
+				{
+					$label = isset($ext['folder'])
+						? $ext['type'] . ':' . $ext['folder'] . '/' . $ext['element']
+						: $ext['type'] . ':' . $ext['element'];
+					$missing[] = $label;
+				}
+			}
+		}
+		catch (\Throwable $e)
+		{
+			Log::add(self::PACKAGE_LABEL . ' install verification failed: ' . $e->getMessage(), Log::ERROR, 'mokosuite');
+			$missing[] = 'verification query failed';
+		}
+
+		return $missing;
+	}
+
+	private function setPackageEnabled(bool $enabled): void
+	{
+		try
+		{
+			$db = Factory::getDbo();
+			$db->setQuery(
+				$db->getQuery(true)
+					->update($db->quoteName('#__extensions'))
+					->set($db->quoteName('enabled') . ' = ' . ($enabled ? 1 : 0))
+					->where($db->quoteName('type') . ' = ' . $db->quote('package'))
+					->where($db->quoteName('element') . ' = ' . $db->quote(self::PACKAGE_ELEMENT))
+			);
+			$db->execute();
+		}
+		catch (\Throwable $e)
+		{
+			Log::add(self::PACKAGE_LABEL . ' failed to toggle package state: ' . $e->getMessage(), Log::ERROR, 'mokosuite');
+		}
+	}
+
 	private function warnMissingLicenseKey(): void
 	{
 		try