Summary

Adopt KCENON_* integration flags in monitoring_system.

5W1H Specification

• Who: monitoring_system maintainers
• What: Replace BUILD_WITH_COMMON_SYSTEM / BUILD_WITH_LOGGER_SYSTEM
• Where: interfaces and adapters
• When: TBD
• Why: Consistent integration detection across systems
• How: Include feature_flags header and update macros

Parent Issue

kcenon/common_system#223

Tasks

• Include feature_flags.h in shared headers
• Replace BUILD_WITH_COMMON_SYSTEM / BUILD_WITH_LOGGER_SYSTEM with KCENON_HAS_*
• Keep legacy mapping if needed for migration

Acceptance Criteria

• Integration gates use KCENON_HAS_*
• Legacy options continue to work during migration