5W1H Specification

• Who: thread_system maintainers.
• What: Replace thread_system-specific monitoring interfaces with common_system monitoring contracts.
• Where: include/kcenon/thread/interfaces/monitoring_interface.h, monitorable_interface.h, thread_context.h, and metrics reporting call-sites.
• When: v3.0.0.
• Why: A single monitoring contract (kcenon::common::interfaces) is required for ecosystem-wide observability.
• How: Use kcenon::common::interfaces::IMonitor for metric emission and optionally implement IMonitorable for components.

Tasks

• Replace kcenon::thread::monitoring_interface::* usage with kcenon::common::interfaces::{IMonitor, metrics_snapshot, health_check_result, thread_pool_metrics, worker_metrics, system_metrics}.
• Decide mapping strategy:
  • Option A: thread_pool implements common::interfaces::IMonitorable.
  • Option B: thread_context translates thread_pool metrics → IMonitor::record_metric() calls with tags.
• Remove include/kcenon/thread/interfaces/monitoring_interface.h and monitorable_interface.h from installed surface (or move to compat-only).
• Update thread_context to carry std::shared_ptr<common::interfaces::IMonitor>.

Acceptance Criteria

• No installed header references kcenon::thread::monitoring_interface or kcenon::thread::monitorable_interface.
• Monitoring integration works with kcenon/monitoring_system via common interfaces.

Related Completed Issues

• Enforce common_system dependency and add runtime metrics #129: Enforce common_system dependency + runtime metrics baseline
• feat(phase2): deprecate monitoring interface types (Task 2.3) #191: Deprecate monitoring interface types
• feat: add common_system integration adapters #197: Add common_system integration adapters