Add structured logging, metrics, and tracing support

[agramms]

📊 Objective

Implement comprehensive observability features including structured logging, metrics collection, and distributed tracing to enable effective monitoring and debugging of JDPI client operations.

🔍 Current State

• Basic logging with Ruby Logger
• No structured metrics collection
• Limited debugging capabilities
• No distributed tracing support

🎯 Observability Goals

1. Structured Logging

• JSON-formatted log output
• Consistent log levels and formats
• Request/response correlation IDs
• Sensitive data redaction
• Performance metrics in logs

2. Metrics Collection

• Request latency and throughput
• Error rates and types
• Token cache hit/miss rates
• Storage backend performance
• Business metrics (payments, key registrations)

3. Distributed Tracing

• OpenTelemetry integration
• Request trace correlation
• Cross-service span tracking
• Performance bottleneck identification
• Error trace analysis

4. Health Monitoring

• Health check endpoints
• Service dependency monitoring
• Circuit breaker status
• Resource utilization tracking

🏆 Success Criteria

• Structured JSON logging implemented
• Comprehensive metrics collection working
• OpenTelemetry tracing functional
• Health monitoring endpoints available
• Grafana dashboard configured
• Alerting rules defined and tested
• Performance impact < 5% overhead
• Documentation and runbooks complete