Add import/export and update system

Implement CSV/JSON import and export for domains, notification groups and tags (with masking for sensitive channel data), including size/format validation, in-memory CSV building, and logging. Add tag transfer and bulk transfer actions (admin-only). Introduce a new update system: Add UpdateController and UpdateService, migration 025_add_update_system_v1.1.3.sql, and installer changes to include the new migration and version handling; provide endpoints to check, apply, rollback and configure updates. Update helpers and UI bits: add getUpdateBadgeInfo in LayoutHelper, update notification icons/redirects, and add getMaxUploadSize in ViewHelper. Misc: add NotificationGroup::findByName, tweak .gitignore backups path, and update related views and routes.

app/Helpers/ViewHelper.php

@@ -138,6 +138,37 @@ class ViewHelper
         return $html;
     }
 
+    /**
+     * Get the PHP max upload size from ini settings.
+     * Returns the lower of upload_max_filesize and post_max_size as a human-readable string.
+     *
+     * @return string Human-readable size (e.g. "128 MB")
+     */
+    public static function getMaxUploadSize(): string
+    {
+        $phpUploadMax = self::parseIniSize(ini_get('upload_max_filesize') ?: '2M');
+        $phpPostMax = self::parseIniSize(ini_get('post_max_size') ?: '8M');
+        $phpLimit = min($phpUploadMax, $phpPostMax);
+
+        return self::formatBytes($phpLimit, 0);
+    }
+
+    /**
+     * Parse a PHP ini size value (e.g. "2M", "128K", "1G") into bytes.
+     */
+    private static function parseIniSize(string $size): int
+    {
+        $value = (int) $size;
+        $unit = strtolower(substr(trim($size), -1));
+
+        return match ($unit) {
+            'g' => $value * 1073741824,
+            'm' => $value * 1048576,
+            'k' => $value * 1024,
+            default => $value,
+        };
+    }
+
     /**
      * Generate alert message HTML
      */