Implement language-specific content system

- Rename guide files: nl.md → nl.codepress.md, en.md → uk.codepress.md
- Add language filtering in scanDirectory() for nl.* and uk.* files/folders
- Update formatDisplayName() to remove language prefixes from display names
- Update getGuidePage() to use new naming convention (en → uk mapping)
- Content with nl. prefix only shows when Dutch language is selected
- Content with uk. prefix only shows when English language is selected

engine/core/class/CodePressCMS.php

@@ -109,6 +109,15 @@ class CodePressCMS {
         foreach ($items as $item) {
             if ($item[0] === '.') continue;
             
+            // Skip language-specific content that doesn't match current language
+            if (preg_match('/^(nl|uk)\./', $item)) {
+                $langPrefix = substr($item, 0, 2);
+                if (($langPrefix === 'nl' && $this->currentLanguage !== 'nl') ||
+                    ($langPrefix === 'uk' && $this->currentLanguage !== 'en')) {
+                    continue;
+                }
+            }
+            
             $path = $dir . '/' . $item;
             $relativePath = $prefix ? $prefix . '/' . $item : $item;
             
@@ -510,6 +519,11 @@ class CodePressCMS {
      * @return string Formatted display name
      */
     private function formatDisplayName($filename) {
+        // Remove language prefixes (nl. or uk.) from display names
+        if (preg_match('/^(nl|uk)\.(.+)$/', $filename, $matches)) {
+            $filename = $matches[2];
+        }
+        
         // Handle special cases first
         if (strtolower($filename) === 'phpinfo') {
             return 'phpinfo';
@@ -627,10 +641,11 @@ class CodePressCMS {
      */
     private function getGuidePage() {
         $lang = $this->currentLanguage;
-        $guideFile = __DIR__ . '/../../../guide/' . $lang . '.md';
+        $langCode = ($lang === 'en') ? 'uk' : $lang; // Map 'en' to 'uk' for file naming
+        $guideFile = __DIR__ . '/../../../guide/' . $langCode . '.codepress.md';
         
         if (!file_exists($guideFile)) {
-            $guideFile = __DIR__ . '/../../../guide/en.md'; // Fallback to English
+            $guideFile = __DIR__ . '/../../../guide/uk.codepress.md'; // Fallback to English (UK)
         }
         
         $content = file_get_contents($guideFile);