Parent Issue

Closes #406

Summary

Add comprehensive unit tests and integration tests for HTTP/2 server implementation.

Tasks

• Create tests/test_http2_server.cpp for unit tests
• Create tests/integration/test_http2_client_server.cpp for integration tests
• Test server lifecycle (start, stop)
• Test SETTINGS exchange
• Test request/response handling
• Test stream multiplexing
• Test flow control
• Test error handling

Files to Create

• tests/test_http2_server.cpp
• tests/integration/test_http2_client_server.cpp

Acceptance Criteria

• All unit tests pass
• All integration tests pass
• Client-server interoperability verified