feat: Implement centralized audit logging admin interface (refs #10)

- Add audit_logs table with categories, severities, and indexes
- Create AuditLogService and AuditLogRepository
- Add REST API endpoints for viewing and exporting logs
- Wire audit logging into auth, vehicles, admin, and backup features
- Add desktop AdminLogsPage with filters and CSV export
- Add mobile AdminLogsMobileScreen with card layout
- Implement 90-day retention cleanup job
- Remove old AuditLogPanel from AdminCatalogPage

Security fixes:
- Escape LIKE special characters to prevent pattern injection
- Limit CSV export to 5000 records to prevent memory exhaustion
- Add truncation warning headers for large exports

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/src/core/scheduler/index.ts

@@ -15,6 +15,10 @@ import {
   processBackupRetention,
   setBackupCleanupJobPool,
 } from '../../features/backup/jobs/backup-cleanup.job';
+import {
+  processAuditLogCleanup,
+  setAuditLogCleanupJobPool,
+} from '../../features/audit-log/jobs/cleanup.job';
 import { pool } from '../config/database';
 
 let schedulerInitialized = false;
@@ -31,6 +35,9 @@ export function initializeScheduler(): void {
   setBackupJobPool(pool);
   setBackupCleanupJobPool(pool);
 
+  // Initialize audit log cleanup job pool
+  setAuditLogCleanupJobPool(pool);
+
   // Daily notification processing at 8 AM
   cron.schedule('0 8 * * *', async () => {
     logger.info('Running scheduled notification job');
@@ -90,8 +97,30 @@ export function initializeScheduler(): void {
     }
   });
 
+  // Audit log retention cleanup at 3 AM daily (90-day retention)
+  cron.schedule('0 3 * * *', async () => {
+    logger.info('Running audit log cleanup job');
+    try {
+      const result = await processAuditLogCleanup();
+      if (result.success) {
+        logger.info('Audit log cleanup job completed', {
+          deletedCount: result.deletedCount,
+          retentionDays: result.retentionDays,
+        });
+      } else {
+        logger.error('Audit log cleanup job failed', {
+          error: result.error,
+        });
+      }
+    } catch (error) {
+      logger.error('Audit log cleanup job failed', {
+        error: error instanceof Error ? error.message : String(error)
+      });
+    }
+  });
+
   schedulerInitialized = true;
-  logger.info('Cron scheduler initialized - notification (8 AM), account purge (2 AM), backup check (every min), retention cleanup (4 AM)');
+  logger.info('Cron scheduler initialized - notification (8 AM), account purge (2 AM), audit log cleanup (3 AM), backup check (every min), retention cleanup (4 AM)');
 }
 
 export function isSchedulerInitialized(): boolean {