Create Event Processing Worker

# 🧠 Concept
Handle blockchain events asynchronously.

## ⚠️ Problem
Monitoring pipelines require scalable processing.

## 📁 Implementation Scope
- src/workers/events/

## ✅ Requirements
- Consume queue jobs
- Process events
- Persist results

## 🎯 Acceptance Criteria
- [ ] Worker operational
- [ ] Events processed
- [ ] Failures handled