[Security] Bump sequelize and undici to fix high-severity vulnerabilities (#138)
* [Code Simplification] Replace Kafka with BullMQ for item submission processing
* [Security] Bump sequelize and undici to fix high-severity vulnerabilities
- sequelize 6.32.1 → 6.37.8: fixes SQL injection via JSON column cast type (GHSA)
- undici 7.19.0 → 7.24.5: fixes WebSocket memory/DoS, CRLF injection, and HTTP smuggling
- Lockfile-only changes, no package.json or source code modifications
* Raise minimum versions for sequelize and undici in package.json