docs: add inline documentation where missing

src/Logger/DatabaseHandler.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace App\Logger;
 
 use App\Entity\LogEntry;
@@ -7,6 +9,12 @@ use Doctrine\ORM\EntityManagerInterface;
 use Monolog\Handler\AbstractProcessingHandler;
 use Monolog\LogRecord;
 
+/**
+ * Monolog handler that persists log entries to the database.
+ *
+ * Writes log records to the LogEntry entity, replacing message placeholders
+ * with context values. Includes channel, context, and extra data for auditing.
+ */
 class DatabaseHandler extends AbstractProcessingHandler
 {
     public function __construct(private readonly EntityManagerInterface $entityManager)