Add support for handling /files/ requests and temp file attachments in file_server.php

- Updated `file_server.php` to mark files with `temp_file_` in their name as attachments.
- Enhanced routing logic in `index.php` to load `file_server.php` for `/files/` requests.

services/nginx/app/file_server.php

@@ -18,6 +18,10 @@ if (preg_match('/\.pdf$/', $file)) {
         $isAttachment = true;
     }
 }
+// Check if the file is an attachment
+if (str_contains($file, 'temp_file_')) {
+    $isAttachment = true;
+}
 if ($isPDF && $isPDFStore) {
     $file = str_replace('/modules/washcertificates/output/certificates/', '', $file);