refactor(deployment): Remove WireGuard VPN dependency and restore public service access

Remove WireGuard integration from production deployment to simplify infrastructure:
- Remove docker-compose-direct-access.yml (VPN-bound services)
- Remove VPN-only middlewares from Grafana, Prometheus, Portainer
- Remove WireGuard middleware definitions from Traefik
- Remove WireGuard IPs (10.8.0.0/24) from Traefik forwarded headers

All monitoring services now publicly accessible via subdomains:
- grafana.michaelschiemer.de (with Grafana native auth)
- prometheus.michaelschiemer.de (with Basic Auth)
- portainer.michaelschiemer.de (with Portainer native auth)

All services use Let's Encrypt SSL certificates via Traefik.

tests/debug/test-generator-polynomial.php

@@ -0,0 +1,68 @@
+<?php
+
+declare(strict_types=1);
+
+require_once __DIR__ . '/../../vendor/autoload.php';
+
+use App\Framework\QrCode\ErrorCorrection\ReedSolomonEncoder;
+
+echo "=== Generator Polynomial Verification ===\n\n";
+
+$rs = new ReedSolomonEncoder();
+$reflection = new ReflectionClass($rs);
+
+// Get generator polynomial for 10 EC codewords
+$getGeneratorMethod = $reflection->getMethod('getGeneratorPolynomial');
+$getGeneratorMethod->setAccessible(true);
+$generator = $getGeneratorMethod->invoke($rs, 10);
+
+echo "Current generator polynomial (10 EC codewords):\n";
+echo "  [" . implode(', ', $generator) . "]\n\n";
+
+// Expected from QR code specification
+$expected = [0, 251, 67, 46, 61, 118, 70, 64, 94, 32, 45];
+
+echo "Expected generator polynomial:\n";
+echo "  [" . implode(', ', $expected) . "]\n\n";
+
+if ($generator === $expected) {
+    echo "✅ Generator polynomial matches!\n\n";
+} else {
+    echo "❌ Generator polynomial doesn't match!\n";
+    echo "Differences:\n";
+    for ($i = 0; $i < min(count($generator), count($expected)); $i++) {
+        if ($generator[$i] !== $expected[$i]) {
+            echo "  Coefficient {$i}: got {$generator[$i]}, expected {$expected[$i]}\n";
+        }
+    }
+    echo "\n";
+}
+
+// Test: Generate polynomial dynamically
+echo "=== Testing Dynamic Generation ===\n";
+$generateMethod = $reflection->getMethod('generateGeneratorPolynomial');
+$generateMethod->setAccessible(true);
+$generated = $generateMethod->invoke($rs, 10);
+
+echo "Dynamically generated:\n";
+echo "  [" . implode(', ', $generated) . "]\n\n";
+
+if ($generated === $expected) {
+    echo "✅ Dynamic generation matches expected!\n";
+} else {
+    echo "❌ Dynamic generation doesn't match!\n";
+    echo "This might be the problem - the generator polynomial is wrong.\n";
+}
+
+// Check if the issue is with the leading coefficient
+// In QR codes, the generator polynomial should be monic (leading coefficient = 1)
+// But our polynomials start with 0
+echo "\n=== Generator Polynomial Format ===\n";
+echo "Note: In our implementation, generator polynomials start with [0, ...]\n";
+echo "This might be correct if we're using a different representation.\n";
+echo "But let's check if the actual polynomial is correct.\n\n";
+
+// The generator polynomial should be: g(x) = (x - α^0)(x - α^1)...(x - α^9)
+// When expanded, this should give us the expected coefficients
+
+