Background

Part of #363 — Phase 4

Verify monitoring_system already fully uses service_container and clean up any remnants.

Current State

monitoring_system already delegates to service_container via service_registration.h adapter.
This phase is primarily verification and cleanup.

Scope

• Verify service_registration.h follows ModuleRegistrar convention
• Remove any vestigial DI code
• Update to use ModuleRegistrar concept if applicable
• Verify all monitoring_system tests pass

Acceptance Criteria

• No internal DI containers remain
• service_registration.h follows ecosystem conventions
• All tests pass under ASAN and TSAN