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-quiet-zone-svg.php

@@ -0,0 +1,74 @@
+<?php
+
+declare(strict_types=1);
+
+require_once __DIR__ . '/../../vendor/autoload.php';
+
+use App\Framework\QrCode\QrCodeGenerator;
+use App\Framework\QrCode\QrCodeRenderer;
+use App\Framework\QrCode\ValueObjects\ErrorCorrectionLevel;
+use App\Framework\QrCode\ValueObjects\QrCodeConfig;
+use App\Framework\QrCode\ValueObjects\QrCodeVersion;
+use App\Framework\QrCode\ValueObjects\EncodingMode;
+use App\Framework\QrCode\ValueObjects\QrCodeStyle;
+
+echo "=== Testing Quiet Zone in SVG ===\n\n";
+
+$testData = 'HELLO WORLD';
+$config = new QrCodeConfig(
+    version: QrCodeVersion::fromNumber(1),
+    errorCorrectionLevel: ErrorCorrectionLevel::M,
+    encodingMode: EncodingMode::BYTE
+);
+
+$matrix = QrCodeGenerator::generate($testData, $config);
+$size = $matrix->getSize();
+
+echo "Matrix size: {$size}x{$size}\n\n";
+
+// Test different styles
+$styles = [
+    'default' => QrCodeStyle::default(),
+    'large' => QrCodeStyle::large(),
+];
+
+foreach ($styles as $name => $style) {
+    echo "=== Style: {$name} ===\n";
+    echo "Module size: {$style->moduleSize}px\n";
+    echo "Quiet zone size: {$style->quietZoneSize} modules\n";
+    echo "Include quiet zone: " . ($style->includeQuietZone ? 'YES' : 'NO') . "\n";
+    
+    $canvasSize = $style->calculateCanvasSize($size);
+    $offset = $style->getQuietZoneOffset();
+    
+    echo "Canvas size: {$canvasSize}x{$canvasSize}px\n";
+    echo "Quiet zone offset: {$offset}px\n";
+    echo "QR code area: " . ($size * $style->moduleSize) . "x" . ($size * $style->moduleSize) . "px\n";
+    echo "Quiet zone border: {$offset}px on each side\n\n";
+    
+    // Generate SVG
+    $renderer = new QrCodeRenderer();
+    $svg = $renderer->renderSvg($matrix, $style);
+    
+    // Check if quiet zone is present in SVG
+    $hasQuietZone = $offset > 0;
+    $quietZoneInSvg = strpos($svg, "width=\"{$canvasSize}\"") !== false;
+    
+    echo "SVG has quiet zone: " . ($quietZoneInSvg ? 'YES' : 'NO') . "\n";
+    
+    // Save SVG
+    $filename = "/var/www/html/tests/debug/qr-{$name}.svg";
+    file_put_contents($filename, $svg);
+    echo "SVG saved to: {$filename}\n";
+    echo "SVG size: " . strlen($svg) . " bytes\n\n";
+}
+
+echo "=== Quiet Zone Requirements ===\n";
+echo "ISO/IEC 18004 requires:\n";
+echo "- Minimum 4 modules quiet zone on all sides\n";
+echo "- Quiet zone must be white/light color\n";
+echo "- Quiet zone must be free of any markings\n\n";
+
+echo "✅ Quiet zone should be correct if offset > 0 and background is light color.\n";
+
+