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-rs-with-reference-ec.php

@@ -0,0 +1,89 @@
+<?php
+
+declare(strict_types=1);
+
+require_once __DIR__ . '/../../vendor/autoload.php';
+
+use App\Framework\QrCode\ErrorCorrection\ReedSolomonEncoder;
+
+echo "=== RS EC Codewords Reference Test ===\n\n";
+
+// Known reference data codewords for "HELLO WORLD" Version 1, Level M
+// From QR code specification examples
+$referenceDataCodewords = [64, 180, 132, 84, 196, 196, 242, 5, 116, 245, 174, 59, 64, 109, 236, 233];
+
+// But wait - our encoding produces different codewords starting at index 10
+// Let's check what our actual encoding produces
+$ourDataCodewords = [64, 180, 132, 84, 196, 196, 242, 5, 116, 245, 36, 196, 64, 236, 17, 236];
+
+echo "Reference data codewords (from spec):\n";
+echo implode(', ', $referenceDataCodewords) . "\n\n";
+
+echo "Our data codewords:\n";
+echo implode(', ', $ourDataCodewords) . "\n\n";
+
+// Compare
+echo "Differences:\n";
+for ($i = 0; $i < min(count($referenceDataCodewords), count($ourDataCodewords)); $i++) {
+    if ($referenceDataCodewords[$i] !== $ourDataCodewords[$i]) {
+        echo "  Codeword {$i}: reference={$referenceDataCodewords[$i]}, ours={$ourDataCodewords[$i]}\n";
+    }
+}
+echo "\n";
+
+// Now test RS encoding with reference data codewords
+echo "=== Testing RS with Reference Data Codewords ===\n";
+$rs = new ReedSolomonEncoder();
+$ecCodewords = 10;
+
+$referenceEC = $rs->encode($referenceDataCodewords, $ecCodewords);
+echo "EC codewords (from reference data): " . implode(', ', $referenceEC) . "\n\n";
+
+// Test RS encoding with our data codewords
+$ourEC = $rs->encode($ourDataCodewords, $ecCodewords);
+echo "EC codewords (from our data): " . implode(', ', $ourEC) . "\n\n";
+
+// Verify both with decoder
+require_once __DIR__ . '/test-reed-solomon-decoder.php';
+$decoder = new SimpleRSDecoder();
+
+// Test reference
+$fullReference = array_merge($referenceDataCodewords, $referenceEC);
+$syndromesRef = $decoder->calculateSyndromes($fullReference, $ecCodewords);
+echo "Reference syndromes: " . implode(', ', $syndromesRef) . "\n";
+$allZeroRef = true;
+foreach ($syndromesRef as $s) {
+    if ($s !== 0) {
+        $allZeroRef = false;
+        break;
+    }
+}
+echo ($allZeroRef ? "✅" : "❌") . " Reference codewords are " . ($allZeroRef ? "valid" : "invalid") . "\n\n";
+
+// Test ours
+$fullOurs = array_merge($ourDataCodewords, $ourEC);
+$syndromesOurs = $decoder->calculateSyndromes($fullOurs, $ecCodewords);
+echo "Our syndromes: " . implode(', ', $syndromesOurs) . "\n";
+$allZeroOurs = true;
+foreach ($syndromesOurs as $s) {
+    if ($s !== 0) {
+        $allZeroOurs = false;
+        break;
+    }
+}
+echo ($allZeroOurs ? "✅" : "❌") . " Our codewords are " . ($allZeroOurs ? "valid" : "invalid") . "\n\n";
+
+// Now try to find expected EC codewords from known sources
+echo "=== Finding Expected EC Codewords ===\n";
+echo "If we can find a working QR code generator or reference implementation,\n";
+echo "we can compare our EC codewords with the expected ones.\n\n";
+
+// Known EC codewords from QR code specification for "HELLO WORLD"
+// These are from the ISO/IEC 18004 specification example
+// But we need to verify if our data codewords match first
+
+// The issue is: our data codewords don't match the reference!
+// This means the problem is in the encoding step, not Reed-Solomon.
+// But let's still test if RS works correctly with correct input.
+
+