[Prod] Add OpenTelemetry integration

[iAziz786]

Description

Observability support

Acceptance Criteria

• Integrate OpenTelemetry tracing
• Add distributed trace correlation
• Implement metrics export via OTLP
• Support multiple telemetry backends
• Add trace sampling configuration

Implementation Hints

• Use OpenTelemetry Go SDK
• Implement trace context propagation
• Add instrumentation for key operations

Dependencies

Performance metrics, Structured logging