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-data-codewords-detail.php

@@ -0,0 +1,104 @@
+<?php
+
+declare(strict_types=1);
+
+echo "=== Data Codewords Detail Analysis ===\n\n";
+
+$testData = 'HELLO WORLD';
+
+// Build our encoding
+$bits = '';
+
+// 1. Mode indicator (4 bits) - Byte mode = 0100
+$bits .= '0100';
+
+// 2. Character count (8 bits)
+$bits .= str_pad(decbin(11), 8, '0', STR_PAD_LEFT);
+
+// 3. Data bytes - let's check each one
+echo "Data bytes:\n";
+for ($i = 0; $i < 11; $i++) {
+    $char = $testData[$i];
+    $byte = ord($char);
+    $byteBits = str_pad(decbin($byte), 8, '0', STR_PAD_LEFT);
+    $bits .= $byteBits;
+    echo "  '{$char}' (ASCII {$byte}): {$byteBits}\n";
+}
+
+echo "\nTotal bits: " . strlen($bits) . "\n";
+echo "Bit string: {$bits}\n\n";
+
+// Convert to codewords
+$codewords = [];
+for ($i = 0; $i < strlen($bits); $i += 8) {
+    if ($i + 8 <= strlen($bits)) {
+        $byte = substr($bits, $i, 8);
+        $codewords[] = bindec($byte);
+        echo "Codeword " . count($codewords) . " (bits " . $i . "-" . ($i+7) . "): {$byte} = " . bindec($byte) . "\n";
+    } else {
+        // Partial byte
+        $byte = substr($bits, $i);
+        echo "Partial byte (bits " . $i . "-" . (strlen($bits)-1) . "): {$byte}\n";
+    }
+}
+
+// Expected codewords
+$expected = [64, 180, 132, 84, 196, 196, 242, 5, 116, 245, 174, 59, 64, 109, 236, 233];
+
+echo "\n=== Expected Codewords ===\n";
+$expectedBits = '';
+for ($i = 0; $i < count($expected); $i++) {
+    $byteBits = str_pad(decbin($expected[$i]), 8, '0', STR_PAD_LEFT);
+    $expectedBits .= $byteBits;
+    echo "Codeword " . ($i + 1) . ": {$byteBits} = {$expected[$i]}\n";
+}
+
+echo "\n=== Comparison ===\n";
+echo "Our bit string (first 100 bits):\n";
+echo substr($bits, 0, 100) . "\n\n";
+echo "Expected bit string (first 100 bits):\n";
+echo substr($expectedBits, 0, 100) . "\n\n";
+
+// Find first difference
+for ($i = 0; $i < min(strlen($bits), 100); $i++) {
+    if ($bits[$i] !== $expectedBits[$i]) {
+        $codewordIndex = intval($i / 8);
+        $bitInCodeword = $i % 8;
+        echo "❌ First difference at bit {$i} (codeword " . ($codewordIndex + 1) . ", bit {$bitInCodeword})\n";
+        echo "   Our bit: {$bits[$i]}\n";
+        echo "   Expected: {$expectedBits[$i]}\n";
+        
+        // Show codeword context
+        $codewordStart = $codewordIndex * 8;
+        echo "   Codeword " . ($codewordIndex + 1) . ":\n";
+        echo "     Our:      " . substr($bits, $codewordStart, 8) . " = " . (isset($codewords[$codewordIndex]) ? $codewords[$codewordIndex] : 'N/A') . "\n";
+        echo "     Expected: " . substr($expectedBits, $codewordStart, 8) . " = " . $expected[$codewordIndex] . "\n";
+        
+        // Show surrounding context
+        echo "   Context (bits " . max(0, $codewordStart - 8) . "-" . min(strlen($bits), $codewordStart + 16) . "):\n";
+        echo "     Our:      " . substr($bits, max(0, $codewordStart - 8), min(24, strlen($bits) - max(0, $codewordStart - 8))) . "\n";
+        echo "     Expected: " . substr($expectedBits, max(0, $codewordStart - 8), min(24, strlen($expectedBits) - max(0, $codewordStart - 8))) . "\n";
+        break;
+    }
+}
+
+// Check if our data matches expected data
+echo "\n=== Data Codewords Check ===\n";
+echo "Our first 12 codewords: " . implode(', ', array_slice($codewords, 0, 12)) . "\n";
+echo "Expected first 12 codewords: " . implode(', ', array_slice($expected, 0, 12)) . "\n";
+
+$match = true;
+for ($i = 0; $i < min(12, count($codewords), count($expected)); $i++) {
+    if ($codewords[$i] !== $expected[$i]) {
+        $match = false;
+        echo "❌ Codeword " . ($i + 1) . " differs: ours={$codewords[$i]}, expected={$expected[$i]}\n";
+    }
+}
+
+if ($match) {
+    echo "✅ First 12 codewords match!\n";
+} else {
+    echo "❌ Data codewords don't match!\n";
+}
+
+