Add audit trail: AuditLog entity, AuditService, admin logs page

- AuditLog entity: action, entityType, entityId, data (JSON), performedBy, ipAddress
- AuditService: logs actions with current user and IP
- Audit on: order_created, order_paid, order_cancelled, order_refunded
- Admin /admin/logs: paginated table with action badges, details, user, IP
- Navigation link 'Logs' in admin header

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

migrations/Version20260322120000.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+final class Version20260322120000 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Create audit_log table';
+    }
+
+    public function up(Schema $schema): void
+    {
+        $this->addSql('CREATE TABLE audit_log (id INT GENERATED BY DEFAULT AS IDENTITY NOT NULL, action VARCHAR(50) NOT NULL, entity_type VARCHAR(255) NOT NULL, entity_id INT DEFAULT NULL, data JSON NOT NULL, performed_by VARCHAR(255) DEFAULT NULL, ip_address VARCHAR(45) DEFAULT NULL, created_at TIMESTAMP(0) WITHOUT TIME ZONE NOT NULL, PRIMARY KEY(id))');
+        $this->addSql('CREATE INDEX IDX_AUDIT_ACTION ON audit_log (action)');
+        $this->addSql('CREATE INDEX IDX_AUDIT_CREATED ON audit_log (created_at)');
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('DROP TABLE audit_log');
+    }
+}