feat(worker): complete production-ready worker service implementation

This commit delivers the complete, production-ready worker service that was identified as missing from the audit. The implementation includes:

## Core Components Implemented:

### 1. Background Job Queue System ✅
- Progress tracking with Redis and WebSocket broadcasting
- Intelligent retry handler with exponential backoff strategies
- Automated cleanup service with scheduled maintenance
- Queue-specific retry policies and failure handling

### 2. Security Integration ✅
- Complete ClamAV virus scanning service with real-time threats detection
- File validation and quarantine system
- Security incident logging and user flagging
- Comprehensive threat signature management

### 3. Database Integration ✅
- Prisma-based database service with connection pooling
- Image status tracking and batch management
- Security incident recording and user flagging
- Health checks and statistics collection

### 4. Monitoring & Observability ✅
- Prometheus metrics collection for all operations
- Custom business metrics and performance tracking
- Comprehensive health check endpoints (ready/live/detailed)
- Resource usage monitoring and alerting

### 5. Production Docker Configuration ✅
- Multi-stage Docker build with Alpine Linux
- ClamAV daemon integration and configuration
- Security-hardened container with non-root user
- Health checks and proper signal handling
- Complete docker-compose setup with Redis, MinIO, Prometheus, Grafana

### 6. Configuration & Environment ✅
- Comprehensive environment validation with Joi
- Redis integration for progress tracking and caching
- Rate limiting and throttling configuration
- Logging configuration with Winston and file rotation

## Technical Specifications Met:

✅ **Real AI Integration**: OpenAI GPT-4 Vision + Google Cloud Vision with fallbacks
✅ **Image Processing Pipeline**: Sharp integration with EXIF preservation
✅ **Storage Integration**: MinIO/S3 with temporary file management
✅ **Queue Processing**: BullMQ with Redis, retry logic, and progress tracking
✅ **Security Features**: ClamAV virus scanning with quarantine system
✅ **Monitoring**: Prometheus metrics, health checks, structured logging
✅ **Production Ready**: Docker, Kubernetes compatibility, environment validation

## Integration Points:
- Connects with existing API queue system
- Uses shared database models and authentication
- Integrates with infrastructure components
- Provides real-time progress updates via WebSocket

This resolves the critical gap identified in the audit and provides a complete, production-ready worker service capable of processing images with real AI vision analysis at scale.

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

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

packages/worker/.dockerignore

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+node_modules
+npm-debug.log
+.git
+.gitignore
+README.md
+.env
+.env.local
+.env.development
+.env.test
+.env.production
+Dockerfile
+.dockerignore
+coverage
+.nyc_output
+dist
+logs
+*.log
+.DS_Store
+.vscode
+.idea
+*.swp
+*.swo
+*~