fix: CLI backups no longer named joomla.invalid (host placeholder)

Joomla's console fills $_SERVER['HTTP_HOST'] with the reserved sentinel
'joomla.invalid', which the [HOST] placeholder resolver used verbatim
because its unusable-host check only knew about empty/localhost. Treat
'joomla.invalid' as unusable too, falling back to live_site then the
system hostname, so CLI/console/scheduled backups get a real name.

Claude-Session: https://claude.ai/code/session_01WbGBN9VyRK61zczYWcCQ2i

source/packages/com_mokosuitebackup/src/Engine/PlaceholderResolver.php

@@ -52,15 +52,25 @@ class PlaceholderResolver
 	{
 		$now      = new \DateTimeImmutable('now');
 
-		/* Resolve hostname: prefer HTTP_HOST (web), then try Joomla config (CLI), then system hostname */
-		$rawHost = $_SERVER['HTTP_HOST'] ?? $_SERVER['SERVER_NAME'] ?? '';
+		/* Resolve hostname: prefer the real request host (web), then the
+		   configured live_site (CLI), then the system hostname. Joomla's console
+		   fills the request host with the placeholder 'joomla.invalid' (an
+		   RFC 6761 reserved TLD used as a CLI sentinel), so treat that — along
+		   with empty/localhost — as unusable and fall through; otherwise every
+		   CLI-triggered backup would be named 'joomla.invalid_…'. */
+		$unusable = static function (string $h): bool {
+			$h = strtolower(trim($h));
 
-		if (empty($rawHost) || $rawHost === 'localhost') {
+			return $h === '' || $h === 'localhost' || $h === 'joomla.invalid';
+		};
+
+		$rawHost = (string) ($_SERVER['HTTP_HOST'] ?? $_SERVER['SERVER_NAME'] ?? '');
+
+		if ($unusable($rawHost)) {
 			try {
-				$app = Factory::getApplication();
-				$liveSite = $app->get('live_site', '');
+				$liveSite = (string) Factory::getApplication()->get('live_site', '');
 
-				if (!empty($liveSite)) {
+				if ($liveSite !== '') {
 					$parsed = parse_url($liveSite, PHP_URL_HOST);
 
 					if (!empty($parsed)) {
@@ -68,12 +78,13 @@ class PlaceholderResolver
 					}
 				}
 			} catch (\Throwable $e) {
-				/* fallback */
+				/* fall through to system hostname */
 			}
 		}
 
-		if (empty($rawHost)) {
-			$rawHost = php_uname('n');
+		if ($unusable($rawHost)) {
+			$sysHost = php_uname('n');
+			$rawHost = $sysHost !== '' ? $sysHost : 'site';
 		}
 
 		$hostname = preg_replace('/[^a-zA-Z0-9._-]/', '', $rawHost);