fix: create payload dir, bundle MokoOnyx ZIP during release build

- Added payload/index.html placeholder
- script.php: look for mokoonyx.zip first, fallback to mokocassiopeia.zip
- auto-release.yml: download MokoOnyx stable ZIP into payload/ during build

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/script.php

@@ -288,20 +288,25 @@ class plgSystemMokoWaaSInstallerScript implements InstallerScriptInterface
 
 		// Template not installed — install from bundled payload
 		$pluginPath = JPATH_PLUGINS . '/system/mokowaas';
-		$payloadZip = $pluginPath . '/payload/mokocassiopeia.zip';
+		$payloadZip = $pluginPath . '/payload/mokoonyx.zip';
+
+		// Fallback to legacy name
+		if (!file_exists($payloadZip)) {
+			$payloadZip = $pluginPath . '/payload/mokocassiopeia.zip';
+		}
 
 		if (!file_exists($payloadZip))
 		{
 			Factory::getApplication()->enqueueMessage(
-				'MokoCassiopeia payload not found at '
-				. $payloadZip,
+				'MokoOnyx payload not found. Please install MokoOnyx manually from '
+				. '<a href="https://git.mokoconsulting.tech/MokoConsulting/MokoOnyx/releases" target="_blank">Gitea Releases</a>.',
 				'warning'
 			);
 
 			return;
 		}
 
-		$tmpDir = JPATH_ROOT . '/tmp/mokocassiopeia';
+		$tmpDir = JPATH_ROOT . '/tmp/mokoonyx';
 
 		try
 		{