ver. 0.300: Manifest-based update system with checksum verification and file backup

Replaces the manual ZIP packaging workflow with an automated build script.
UpdateRepository now supports both manifest JSON format (new) and legacy
_sql.txt/_files.txt format (fallback), enabling a smooth transition for
existing client instances.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

autoload/admin/Controllers/UpdateController.php

@@ -14,9 +14,12 @@ class UpdateController
 
     public function main_view(): string
     {
+        $logContent = @file_get_contents( '../libraries/update_log.txt' );
+
         return \Shared\Tpl\Tpl::view( 'update/main-view', [
             'ver'     => \Shared\Helpers\Helpers::get_version(),
             'new_ver' => \Shared\Helpers\Helpers::get_new_version(),
+            'log'     => $logContent ?: '',
         ] );
     }