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/tests/Unit/Invoicing/EconomicPaymentTermsRouteCollectionExtractionTest.php

@@ -8,7 +8,6 @@ function economic_payment_terms_route_extract_collection(mixed $response): array
 {
     $reflection = new ReflectionClass(economicPaymentTermsRoute::class);
     $target = $reflection->getMethod('extractPaymentTermsCollection');
-    $target->setAccessible(true);
 
     return $target->invokeArgs(null, [$response]);
 }