🚨 Critical: Add integration tests for unified orchestrator

[quantumshiro]

Problem

The unified orchestrator (src/modular/unified_orchestrator.rs) has no integration tests despite being 1,210+ lines of complex layer coordination logic. This is a critical gap identified in CLAUDE.md.

Current Status

• ❌ No integration tests for layer coordination
• ❌ No tests for event-driven architecture with real layers
• ❌ No validation of performance metrics and health monitoring
• ❌ No tests for network integration capabilities

Required Test Coverage

• Event handling across all 17 event types
• Layer coordination and message passing framework
• Performance metrics collection and reporting
• Health monitoring and failure detection
• Network integration with real P2P components
• Error recovery and resilience scenarios
• Multi-layer transaction flow end-to-end

Definition of Done

• Create comprehensive integration test suite
• Tests validate inter-layer communication
• Performance metrics accuracy verified
• Error handling and recovery tested
• All tests pass with cargo test unified_orchestrator --lib

Priority: 🔥 Critical

The orchestrator is the central coordination component - it must be thoroughly tested.

Estimated Effort: 3-4 days