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/tests/Module/Audit/Service/SystemAuditRedactionServiceTest.php

@@ -0,0 +1,42 @@
+<?php
+
+namespace MintyPHP\Tests\Module\Audit\Service;
+
+use MintyPHP\Module\Audit\Service\SystemAuditRedactionService;
+use PHPUnit\Framework\TestCase;
+
+class SystemAuditRedactionServiceTest extends TestCase
+{
+    public function testSensitiveKeysAreRedacted(): void
+    {
+        $service = new SystemAuditRedactionService();
+
+        $redacted = $service->redactMetadata([
+            'email' => 'john@example.com',
+            'token' => 'abc',
+            'active' => 1,
+            'nested' => ['password' => 'secret'],
+        ]);
+
+        $this->assertSame('[REDACTED]', $redacted['email']);
+        $this->assertSame('[REDACTED]', $redacted['token']);
+        $this->assertSame(1, $redacted['active']);
+        $this->assertSame('[REDACTED]', $redacted['nested']['password']);
+    }
+
+    public function testBuildChangeSetUsesAllowlistAndRedactsOtherValues(): void
+    {
+        $service = new SystemAuditRedactionService();
+
+        $changeSet = $service->buildChangeSet(
+            ['active' => 0, 'description' => 'old'],
+            ['active' => 1, 'description' => 'new']
+        );
+
+        $this->assertSame(['active', 'description'], $changeSet['changed_fields']);
+        $this->assertSame(0, $changeSet['changes']['active']['before']);
+        $this->assertSame(1, $changeSet['changes']['active']['after']);
+        $this->assertSame('[REDACTED]', $changeSet['changes']['description']['before']);
+        $this->assertSame('[REDACTED]', $changeSet['changes']['description']['after']);
+    }
+}