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>

tests/Architecture/SecurityLoggingRuntimeContractTest.php

@@ -12,17 +12,18 @@ final class SecurityLoggingRuntimeContractTest extends TestCase
     {
         $violations = array_merge(
             $this->findPatternMatchesInPhpFiles('lib', '/\berror_log\s*\(/'),
-            $this->findPatternMatchesInPhpFiles('pages', '/\berror_log\s*\(/')
+            $this->findPatternMatchesInPhpFiles('pages', '/\berror_log\s*\(/'),
+            $this->findPatternMatchesInPhpFiles('modules', '/\berror_log\s*\(/')
         );
         sort($violations);
 
         self::assertSame(
-            ['pages/admin/frontend-telemetry/ingest().php'],
+            ['modules/audit/pages/admin/frontend-telemetry/ingest().php'],
             $violations,
             "Unexpected error_log() usage outside the telemetry ingest fallback:\n" . implode("\n", $violations)
         );
 
-        $content = $this->readProjectFile('pages/admin/frontend-telemetry/ingest().php');
+        $content = $this->readProjectFile('modules/audit/pages/admin/frontend-telemetry/ingest().php');
         self::assertStringContainsString(
             "error_log('[frontend-telemetry] ingest record_failed request_id=' . RequestContext::id());",
             $content