refactor(audit): extract audit domain into self-contained module

Move the entire audit subsystem (system audit, API audit, import audit,
user lifecycle audit, frontend telemetry) from core into modules/audit/.

Core decoupling via interface-based injection:
- AuditRecorderInterface replaces SystemAuditService in 10+ core services
- UserLifecycleAuditInterface / ImportAuditInterface for specialized flows
- NullAuditRecorder fallback when audit module is disabled
- ApiBootstrap/ApiResponse use null-safe callable resolvers

Module structure (modules/audit/):
- Manifest with routes, permissions, scheduler jobs, authorization policy
- 9 services, 8 repositories, 6 domain enums, 4 job handlers
- 33 page files, 4 JS files, 8 test files, migration scripts, i18n

Core cleanup:
- OperationsAuthorizationPolicy, UiCapabilityMap, PermissionService
  surgically cleaned of audit-specific constants
- Sidebar template cleared of hardcoded audit navigation
- AuditModuleIsolationContractTest ensures no future core→module coupling

All quality gates pass: 1346 tests (19,276 assertions), PHPStan level 5
clean, architecture contracts verified.

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

modules/audit/lib/Module/Audit/Repository/SystemAuditLogRepositoryInterface.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace MintyPHP\Module\Audit\Repository;
+
+/** Contract for system-wide security event logging with channel and outcome filtering. */
+interface SystemAuditLogRepositoryInterface
+{
+    public function create(array $data): int|false;
+
+    public function listPaged(array $filters): array;
+
+    public function listFilterOptions(int $limit = 200): array;
+
+    public function find(int $id): ?array;
+
+    public function purgeOlderThanDays(int $days): int;
+}