Add modular architecture to router

Extract configuration, helpers, content processing, and rendering logic
into separate files

Refactor router to use modular components

app/helpers.php

@@ -0,0 +1,57 @@
+<?php
+
+function extractTitle(string $filePath, string $lang, string $defaultLang): ?string {
+    $files = findAllContentFiles($filePath, $lang, $defaultLang);
+    if (empty($files)) return null;
+
+    // Check the first content file for a title
+    $file = $files[0];
+    $ext = pathinfo($file, PATHINFO_EXTENSION);
+    $content = file_get_contents($file);
+
+    if ($ext === 'md' && preg_match('/^#\s+(.+)$/m', $content, $matches)) {
+        return trim($matches[1]);
+    }
+    if (in_array($ext, ['html', 'php']) && preg_match('/<h1[^>]*>(.*?)<\/h1>/i', $content, $matches)) {
+        return strip_tags($matches[1]);
+    }
+    return null;
+}
+
+function formatNorwegianDate(string $dateString): string {
+    if (preg_match('/^(\d{4})-(\d{2})-(\d{2})/', $dateString, $matches)) {
+        $months = ['januar', 'februar', 'mars', 'april', 'mai', 'juni', 'juli', 'august', 'september', 'oktober', 'november', 'desember'];
+        $day = (int)$matches[3];
+        $month = $months[(int)$matches[2] - 1];
+        $year = $matches[1];
+        return "$day. $month $year";
+    }
+    return $dateString;
+}
+
+function extractDateFromFolder(string $folderName): ?string {
+    if (preg_match('/^(\d{4})-(\d{2})-(\d{2})-/', $folderName, $matches)) {
+        return formatNorwegianDate($matches[1] . '-' . $matches[2] . '-' . $matches[3]);
+    }
+    return null;
+}
+
+function findCoverImage(string $dirPath): ?string {
+    $extensions = ['jpg', 'jpeg', 'png', 'webp', 'gif'];
+    foreach ($extensions as $ext) {
+        if (file_exists("$dirPath/cover.$ext")) {
+            return "cover.$ext";
+        }
+    }
+    return null;
+}
+
+function findPdfFile(string $dirPath): ?string {
+    $files = scandir($dirPath) ?: [];
+    foreach ($files as $file) {
+        if (pathinfo($file, PATHINFO_EXTENSION) === 'pdf') {
+            return $file;
+        }
+    }
+    return null;
+}