initial COmmit: Add KB Antora Importer plugin files

kb-antora-importer/includes/Import/ImportLogger.php

@@ -0,0 +1,61 @@
+<?php
+declare(strict_types=1);
+
+namespace KbAntoraImporter\Import;
+
+final class ImportLogger
+{
+    private const OPTION = 'kb_antora_importer_logs';
+    private const LIMIT = 300;
+
+    public static function info(string $message): void
+    {
+        self::log('INFO', $message);
+    }
+
+    public static function warning(string $message): void
+    {
+        self::log('WARNING', $message);
+    }
+
+    public static function error(string $message): void
+    {
+        update_option('kb_antora_importer_last_error', self::sanitize($message), false);
+        self::log('ERROR', $message);
+    }
+
+    public static function debug(string $message): void
+    {
+        self::log('DEBUG', $message);
+    }
+
+    public static function recent(int $limit = 50): array
+    {
+        $logs = array_reverse((array) get_option(self::OPTION, []));
+        return array_slice($logs, 0, $limit);
+    }
+
+    private static function log(string $level, string $message): void
+    {
+        $logs = (array) get_option(self::OPTION, []);
+        $logs[] = [
+            'time' => current_time('mysql'),
+            'level' => $level,
+            'message' => self::sanitize($message),
+        ];
+
+        if (count($logs) > self::LIMIT) {
+            $logs = array_slice($logs, -self::LIMIT);
+        }
+
+        update_option(self::OPTION, $logs, false);
+    }
+
+    private static function sanitize(string $message): string
+    {
+        $message = preg_replace('/([?&](?:private_)?token=)[^&\s]+/i', '$1[redacted]', $message) ?? $message;
+        $message = preg_replace('/(PRIVATE-TOKEN|Authorization):\s*\S+/i', '$1: [redacted]', $message) ?? $message;
+
+        return sanitize_text_field($message);
+    }
+}