Add unit tests for integration, protocol factory, and remaining modules

[kcenon]

What

Add dedicated unit tests for 13 untested modules: integration bridges (5), protocol factories (4), remaining QUIC (2), HTTP/2 (1), and internal (1). Part of #953.

Scope

Category	Count	Files
Integration	5	container_integration, io_context_thread_manager, logger_integration, monitoring_integration, thread_integration
Protocol Factories	4	quic.cpp, tcp.cpp, udp.cpp, websocket.cpp (in src/protocol/)
QUIC remaining	2	connection_id_manager.cpp, stream_manager.cpp
HTTP/2 remaining	1	http2_server_stream.cpp
Internal	1	websocket_socket.cpp

Why

• Integration modules bridge network_system with external systems (container, logger, monitoring) — untested bridges risk silent failures
• Protocol factory functions are the primary entry points for creating protocol instances
• QUIC connection_id_manager and stream_manager are critical protocol components
• Part of epic Expand unit test coverage from 40% to 80% #953 to raise coverage from 48% to 80%

Where

• Source: src/integration/, src/protocol/, src/protocols/quic/, src/protocols/http2/, src/internal/
• Tests: tests/unit/ (new test files)
• CMake: tests/CMakeLists.txt (register new tests)

How

Technical Approach

1. Create unit test files following existing project patterns
2. Protocol factory tests: verify correct protocol instance creation and configuration
3. QUIC tests: test connection ID management and stream lifecycle
4. Integration tests: mock external system interfaces where needed

Acceptance Criteria

• All 13 modules have dedicated unit test files
• Tests pass on local build
• No GTEST_SKIP() markers
• Tests cover construction, public methods, and error paths

[kcenon]

Implementation Update

Field	Value
PR	#973
Branch	test/issue-968-add-unit-tests-for-integration-protocol-factory-an
Status	In Review (CI pending)

Summary

11 new unit test files added covering all modules specified in this issue. The 2 QUIC modules (connection_id_manager, stream_manager) already had comprehensive tests, so all 13 modules now have dedicated test coverage.

Files Added

• Integration (5): container_integration, io_context_thread_manager, logger_integration, monitoring_integration, thread_integration
• Protocol Factories (4): quic, tcp, udp, websocket
• HTTP/2 (1): http2_server_stream
• Internal (1): websocket_socket

Acceptance Criteria

• All 13 modules have dedicated unit test files
• No GTEST_SKIP() markers
• Tests cover construction, public methods, and error paths
• Tests pass local verification (CI pending)

[kcenon]

Closed via PR #973 (squash merged to develop). All 11 new unit test files added, CI passed on all platforms.