Add WebSocket load performance tests (14 tests, all passing)
✅ COMPLETE: 14/14 tests passing
Test Coverage:
- Concurrent clients: 100/200 client broadcast tests, connection pool efficiency
- Message throughput: Baseline throughput, high-frequency updates, burst handling
- Progress throttling: Throttled updates, network load reduction
- Room isolation: Room isolation performance, selective broadcasts
- Connection stability: Rapid connect/disconnect cycles, concurrent operations
- Memory efficiency: Memory usage with many connections, message queue efficiency
Performance Targets Met:
- 100 clients broadcast: < 2s (target achieved)
- 200 clients broadcast: < 3s (scalability validated)
- Message throughput: > 10 messages/sec baseline (target achieved)
- Connection pool: 50 clients in < 1s (efficiency validated)
- Throttling: 90% message reduction (network optimization confirmed)
- Memory: < 50MB for 100 connections (memory efficient)
All WebSocket load scenarios validated with comprehensive performance metrics.