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-final-fix.php

@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+require_once __DIR__ . '/../../vendor/autoload.php';
+
+use App\Framework\QrCode\ErrorCorrection\ReedSolomonEncoder;
+
+echo "=== Final RS Fix Test ===\n\n";
+
+// The key insight: In QR codes, the polynomial representation might be different
+// Standard RS: c(x) = c[0] + c[1]*x + c[2]*x^2 + ... + c[n-1]*x^(n-1)
+// QR code RS: c(x) = c[0]*x^(n-1) + c[1]*x^(n-2) + ... + c[n-1]*x^0 (MSB-first)
+
+// This means we might need to reverse the codewords for RS encoding/decoding
+
+$data = [64, 180, 132, 84, 196, 196, 242, 5, 116, 245, 36, 196, 64, 236, 17, 236];
+$ecCodewords = 10;
+
+echo "Data codewords: " . implode(', ', $data) . "\n\n";
+
+// Try encoding with data in reverse order (LSB-first representation)
+$reversedData = array_reverse($data);
+echo "Reversed data (for RS encoding): " . implode(', ', $reversedData) . "\n\n";
+
+$rs = new ReedSolomonEncoder();
+$ec = $rs->encode($reversedData, $ecCodewords);
+
+echo "EC codewords (from reversed data): " . implode(', ', $ec) . "\n\n";
+
+// Reverse EC codewords back
+$ecReversed = array_reverse($ec);
+echo "EC codewords (reversed back): " . implode(', ', $ecReversed) . "\n\n";
+
+// Test with decoder - need to reverse everything
+require_once __DIR__ . '/test-reed-solomon-decoder.php';
+
+// For decoder, we also need to reverse
+$decoder = new SimpleRSDecoder();
+$fullCodeword = array_merge($data, $ecReversed);
+$fullReversed = array_reverse($fullCodeword);
+
+$syndromes = $decoder->calculateSyndromes($fullReversed, $ecCodewords);
+
+echo "Syndromes (with reversed codeword): " . implode(', ', $syndromes) . "\n";
+$allZero = true;
+foreach ($syndromes as $s) {
+    if ($s !== 0) {
+        $allZero = false;
+        break;
+    }
+}
+
+if ($allZero) {
+    echo "\n✅ ALL SYNDROMES ARE ZERO!\n";
+    echo "\nThis means we need to reverse codewords for RS encoding!\n";
+} else {
+    echo "\n❌ Still wrong\n";
+}
+
+