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-encoding-exact-structure.php

@@ -0,0 +1,122 @@
+<?php
+
+declare(strict_types=1);
+
+echo "=== Exact Encoding Structure ===\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
+for ($i = 0; $i < 11; $i++) {
+    $byte = ord($testData[$i]);
+    $bits .= str_pad(decbin($byte), 8, '0', STR_PAD_LEFT);
+}
+
+echo "After mode + count + data: " . strlen($bits) . " bits\n";
+
+// Convert to codewords so far
+$codewordsSoFar = [];
+for ($i = 0; $i < strlen($bits); $i += 8) {
+    if ($i + 8 <= strlen($bits)) {
+        $byte = substr($bits, $i, 8);
+        $codewordsSoFar[] = bindec($byte);
+    }
+}
+
+echo "Codewords so far: " . count($codewordsSoFar) . "\n";
+echo implode(', ', $codewordsSoFar) . "\n\n";
+
+// Check: mode + count + data should be exactly 100 bits
+// But we need to check if the last byte is complete
+$remainder = strlen($bits) % 8;
+echo "Remainder after data: {$remainder}\n";
+
+if ($remainder !== 0) {
+    echo "⚠️ Data doesn't end at byte boundary! Last {$remainder} bits incomplete.\n";
+} else {
+    echo "✅ Data ends at byte boundary.\n";
+}
+
+// Expected codewords
+$expected = [64, 180, 132, 84, 196, 196, 242, 5, 116, 245, 174, 59, 64, 109, 236, 233];
+
+// Build expected bit string
+$expectedBits = '';
+foreach ($expected as $cw) {
+    $expectedBits .= str_pad(decbin($cw), 8, '0', STR_PAD_LEFT);
+}
+
+echo "\n=== Comparison ===\n";
+echo "Our bits length: " . strlen($bits) . "\n";
+echo "Expected bits length: " . strlen($expectedBits) . "\n\n";
+
+// Show first 13 codewords (mode + count + data should be 12 codewords = 96 bits)
+// But we have 100 bits, so that's 12.5 codewords?
+echo "First 12 codewords (96 bits):\n";
+echo "Our:      " . substr($bits, 0, 96) . "\n";
+echo "Expected: " . substr($expectedBits, 0, 96) . "\n";
+echo "Match: " . (substr($bits, 0, 96) === substr($expectedBits, 0, 96) ? "✅" : "❌") . "\n\n";
+
+// Show bits 96-104 (this should be the last 4 bits of data + terminator)
+echo "Bits 96-104 (last 4 data bits + terminator):\n";
+echo "Our:      " . substr($bits, 96, 8) . "\n";
+echo "Expected: " . substr($expectedBits, 96, 8) . "\n";
+echo "Match: " . (substr($bits, 96, 8) === substr($expectedBits, 96, 8) ? "✅" : "❌") . "\n\n";
+
+// The issue: After 100 bits of data, we should have:
+// - 4 bits terminator (making 104 bits total)
+// - Then pad to byte (making 104 bits, which is already a multiple of 8)
+// - Then add pad codewords to reach 128 bits (3 pad codewords = 24 bits)
+
+echo "Expected structure:\n";
+echo "  Bits 0-99:   Mode + Count + Data (100 bits)\n";
+echo "  Bits 100-103: Terminator (4 bits)\n";
+echo "  Bits 104-127: Pad codewords (24 bits = 3 codewords)\n\n";
+
+echo "Expected bits 100-127:\n";
+echo substr($expectedBits, 100, 28) . "\n";
+echo "This should be: terminator (4 bits) + padding (24 bits)\n\n";
+
+// Show what our encoding produces
+echo "Our bits 100-127:\n";
+// But we only have 104 bits so far!
+echo "Current length: " . strlen($bits) . " bits\n";
+
+// Add terminator
+$requiredBits = 128;
+$terminatorLength = min(4, max(0, $requiredBits - strlen($bits)));
+$bits .= str_repeat('0', $terminatorLength);
+echo "After terminator ({$terminatorLength} bits): " . strlen($bits) . " bits\n";
+
+// Pad to byte
+$remainder = strlen($bits) % 8;
+if ($remainder !== 0) {
+    $bits .= str_repeat('0', 8 - $remainder);
+}
+echo "After padding to byte: " . strlen($bits) . " bits\n";
+
+// Add pad codewords
+$padBytes = ['11101100', '00010001'];
+$padIndex = 0;
+while (strlen($bits) < $requiredBits) {
+    $bits .= $padBytes[$padIndex % 2];
+    $padIndex++;
+}
+echo "After pad codewords: " . strlen($bits) . " bits\n\n";
+
+echo "Our bits 100-127:\n";
+echo substr($bits, 100, 28) . "\n";
+echo "Expected bits 100-127:\n";
+echo substr($expectedBits, 100, 28) . "\n";
+echo "Match: " . (substr($bits, 100, 28) === substr($expectedBits, 100, 28) ? "✅" : "❌") . "\n";
+
+