Add static file serving from content directory

Only serve non-PHP/HTML/MD files as static assets Check mime type and
serve with appropriate content type

app/router.php

@@ -359,6 +359,18 @@ if (file_exists($assetPath) && is_file($assetPath)) {
     exit;
 }
 
+// Check for static files in content directory
+$contentFilePath = rtrim($contentDir, '/') . '/' . ltrim($requestPath, '/');
+if (file_exists($contentFilePath) && is_file($contentFilePath)) {
+    $ext = pathinfo($contentFilePath, PATHINFO_EXTENSION);
+    // Only serve non-PHP/non-HTML/non-MD files as static assets
+    if (!in_array($ext, ['php', 'html', 'md'])) {
+        header('Content-Type: ' . (mime_content_type($contentFilePath) ?: 'application/octet-stream'));
+        readfile($contentFilePath);
+        exit;
+    }
+}
+
 // Handle frontpage
 if (empty($requestPath)) {
     // Try language-specific frontpage first, then default