Resolve backend Qodana critical and high findings (#314)

Resolve recommended-profile Critical and High findings, retain narrow analyzer exceptions, and update the edge-broker WebSocket dependency to a non-vulnerable release.

services/nginx/app/classes/form.php

@@ -10,7 +10,6 @@ require_once WD . '/modules/forms/form_helper_c.php';
 
 use Exception;
 use forms\form_helper_c;
-use forms\objects\book_interior_wash_f;
 use forms\objects\book_wash_f;
 use objects\form_submissions_o;
 use traits\form_t;