Feature: Security Level mit Notiz für Domains

Implementiert ein Dialog-basiertes UI zum Bearbeiten des Security Levels
mit optionaler Notiz-Funktion für Helpdesk-Domains.

Backend:
- DomainSecurityLevelRepository: CRUD für security_levels mit note-Spalte
- DomainSecurityLevelService: Business-Logik mit Batch-Enrichment
- security-level-data() Endpoint: AJAX + Full-Page POST mit CSRF
- Migration 010: note TEXT-Spalte hinzugefügt
- Bugfix: findByTenantAndDomainNo gibt null bei leerem Array zurück

Frontend (Domain-Liste):
- Badge in Grid klickbar → öffnet Modal-Dialog
- Dialog mit Level-Select + Notiz-Textarea
- AJAX-Save mit Live-Badge-Update ohne Reload
- Event-Delegation für dynamische Grid-Inhalte

Frontend (Domain-Detail):
- Notiz-Feld im Security-Level-Formular
- PRG-Pattern mit Flash-Messages

Core:
- app-http.js: DEFAULT_HEADERS auf XMLHttpRequest für CSRF-Kompatibilität

i18n:
- Keys: Priority, Note, Optional note, Security level updated

Tests:
- DomainSecurityLevelServiceTest: CRUD + Batch-Enrichment

modules/helpdesk/lib/Module/Helpdesk/Repository/DomainSecurityLevelRepository.php

@@ -0,0 +1,155 @@
+<?php
+
+namespace MintyPHP\Module\Helpdesk\Repository;
+
+use MintyPHP\DB;
+
+class DomainSecurityLevelRepository
+{
+    private const ALLOWED_LEVELS = ['niedrig', 'normal', 'hoch', 'kritisch'];
+
+    public function findByTenantAndDomainNo(int $tenantId, string $domainNo): ?array
+    {
+        if ($domainNo === '') {
+            return null;
+        }
+
+        $row = DB::selectOne(
+            'SELECT * FROM helpdesk_domain_security_levels WHERE tenant_id = ? AND domain_no = ? LIMIT 1',
+            (string) $tenantId,
+            $domainNo
+        );
+
+        if (!is_array($row) || $row === []) {
+            return null;
+        }
+        return $row;
+    }
+
+    /**
+     * @param list<string> $domainNos
+     * @return array<string, string> Map of domain_no => security_level
+     */
+    public function listLevelsByDomainNos(int $tenantId, array $domainNos): array
+    {
+        if ($domainNos === []) {
+            return [];
+        }
+
+        $placeholders = implode(',', array_fill(0, count($domainNos), '?'));
+        $params = array_map('strval', $domainNos);
+        $params[] = (string) $tenantId;
+
+        $rows = DB::select(
+            'SELECT domain_no, security_level FROM helpdesk_domain_security_levels WHERE tenant_id = ? AND domain_no IN (' . $placeholders . ')',
+            ...$params
+        );
+
+        $result = [];
+        if (is_array($rows)) {
+            foreach ($rows as $row) {
+                $domainNo = (string) ($row['domain_no'] ?? '');
+                $level = (string) ($row['security_level'] ?? 'normal');
+                if ($domainNo !== '') {
+                    $result[$domainNo] = in_array($level, self::ALLOWED_LEVELS, true) ? $level : 'normal';
+                }
+            }
+        }
+
+        return $result;
+    }
+
+    /**
+     * @param list<string> $domainNos
+     * @return array<string, array{level: string, note: string}> Map of domain_no => {level, note}
+     */
+    public function listDetailsByDomainNos(int $tenantId, array $domainNos): array
+    {
+        if ($domainNos === []) {
+            return [];
+        }
+
+        $placeholders = implode(',', array_fill(0, count($domainNos), '?'));
+        $params = array_map('strval', $domainNos);
+        $params[] = (string) $tenantId;
+
+        $rows = DB::select(
+            'SELECT domain_no, security_level, note FROM helpdesk_domain_security_levels WHERE tenant_id = ? AND domain_no IN (' . $placeholders . ')',
+            ...$params
+        );
+
+        $result = [];
+        if (is_array($rows)) {
+            foreach ($rows as $row) {
+                $domainNo = (string) ($row['domain_no'] ?? '');
+                $level = (string) ($row['security_level'] ?? 'normal');
+                $note = (string) ($row['note'] ?? '');
+                if ($domainNo !== '') {
+                    $result[$domainNo] = [
+                        'level' => in_array($level, self::ALLOWED_LEVELS, true) ? $level : 'normal',
+                        'note' => $note,
+                    ];
+                }
+            }
+        }
+
+        return $result;
+    }
+
+    /**
+     * Insert or update security level for a domain.
+     *
+     * @return bool True on success
+     */
+    public function upsert(int $tenantId, string $domainNo, string $level, ?int $userId, ?string $note = null): bool
+    {
+        if ($domainNo === '' || !in_array($level, self::ALLOWED_LEVELS, true)) {
+            return false;
+        }
+
+        $existing = $this->findByTenantAndDomainNo($tenantId, $domainNo);
+
+        if ($existing !== null) {
+            $result = DB::update(
+                'UPDATE helpdesk_domain_security_levels SET security_level = ?, note = ?, updated_by = ? WHERE tenant_id = ? AND domain_no = ?',
+                $level,
+                $note,
+                $userId !== null ? (string) $userId : null,
+                (string) $tenantId,
+                $domainNo
+            );
+
+            return $result !== false;
+        }
+
+        $result = DB::insert(
+            'INSERT INTO helpdesk_domain_security_levels (tenant_id, domain_no, security_level, note, created_by, updated_by) VALUES (?, ?, ?, ?, ?, ?)',
+            (string) $tenantId,
+            $domainNo,
+            $level,
+            $note,
+            $userId !== null ? (string) $userId : null,
+            $userId !== null ? (string) $userId : null
+        );
+
+        return $result !== false;
+    }
+
+    /**
+     * @api Reserved for future cleanup jobs
+     */
+    public function deleteByTenantAndDomainNo(int $tenantId, string $domainNo): bool
+    {
+        if ($domainNo === '') {
+            return false;
+        }
+
+        $result = DB::update(
+            'DELETE FROM helpdesk_domain_security_levels WHERE tenant_id = ? AND domain_no = ?',
+            (string) $tenantId,
+            $domainNo
+        );
+
+        return $result !== false;
+    }
+}