hotfix: Security, performance, and code cleanup

- Remove hardcoded database password fallback
- Add encryption salt validation (min 32 chars)
- Separate EMAIL_ENCRYPTION_KEY from JWT_SECRET
- Fix command injection in status.service.js (use execFileSync)
- Remove unnecessary SQL injection regex middleware
- Create shared utilities (queryBuilder, pagination, emailAccountHelper)
- Fix N+1 query problems in contact and todo services
- Merge duplicate JMAP config functions
- Add database indexes migration
- Standardize error responses with error codes

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

src/index.js

@@ -1,3 +1,4 @@
+import './config/env.js';
 import app from './app.js';
 import { startAllCronJobs } from './cron/index.js';
 import { logger } from './utils/logger.js';