feat: change log table with retention cron and limits option

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01At3V6SjwbMe6eMzVGW3Hs7

src/ChangeLog/ChangeLogCleanup.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LIT\MCP\ChangeLog;
+
+use LIT\MCP\Limits;
+
+/**
+ * Daily WP-Cron job that removes log rows older than the configured retention.
+ */
+final class ChangeLogCleanup
+{
+    public const HOOK = 'lit_mcp_log_cleanup';
+
+    public function __construct(private ChangeLog $log, private Limits $limits)
+    {
+    }
+
+    public function register(): void
+    {
+        add_action(self::HOOK, [$this, 'run']);
+        add_action('init', [$this, 'ensureScheduled']);
+    }
+
+    public function ensureScheduled(): void
+    {
+        if (wp_next_scheduled(self::HOOK) === false) {
+            wp_schedule_event(time() + 3600, 'daily', self::HOOK);
+        }
+    }
+
+    public function run(): void
+    {
+        $this->log->purgeOlderThan($this->limits->logRetentionDays());
+    }
+}