Improvement: Add Component Integration Tests (CIT) for time_daemon/time_slave and Module Integration Tests (MIT) #56

Purpose

• time_daemon and time_slave currently only have unit tests; component-level and cross-component integration test coverage is missing
• CIT verifies end-to-end component behavior: state-machine transitions, I/O boundary conditions, error-handling paths
• MIT verifies the cross-component data path: time_slave → shared memory IPC → time_daemon
• Establishing CIT/MIT infrastructure enables future feature scenarios to be added with low friction

Scope

• time_daemon CIT — C++ scenarios + Python pytest
• time_slave CIT — gPTP protocol stack component tests
• MIT (Feature Integration Tests) — cross-component tests
• Infrastructure

Out of Scope

• Additional unit tests (UT) — tracked separately
• Requirement-traceability decorators
• End-to-end tests on real hardware / PHC clock — requires hardware environment

Deliverables

• This Improvement introduces a complete Component Integration Test (CIT) and Module Integration Test (MIT) suite for the score_time module, built on the Eclipse SCORE score_test_scenarios framework (v0.3.0). It covers both components (time_daemon, time_slave) and the gPTP shared-memory IPC pipeline between them.

Acceptance criteria

• Test specification and implementation exist. Test passes.