Summary

Implements the placeholder service registration methods in unified_bootstrapper to support conditional service registration based on compile-time feature detection and runtime configuration.

Changes Made

• Added #include "../config/feature_system_deps.h" for feature detection macros
• Enhanced register_core_services() with clear documentation about future extensibility
• Implemented register_optional_services() with conditional compilation support:
  • Logger system integration (via KCENON_WITH_LOGGER_SYSTEM)
  • Monitoring system integration (via KCENON_WITH_MONITORING_SYSTEM)
  • Database system integration (via KCENON_WITH_DATABASE_SYSTEM)
  • Network system integration (via KCENON_WITH_NETWORK_SYSTEM)
• Used [[maybe_unused]] attribute to prevent compiler warnings
• Added comprehensive inline documentation explaining adapter integration pattern

Technical Approach

The implementation uses a two-level conditional check:

1. Runtime check: bootstrapper_options flags (enable_logging, enable_monitoring, etc.)
2. Compile-time check: Feature detection macros (KCENON_WITH_*_SYSTEM)

This allows graceful degradation when subsystems are not available, enabling the bootstrapper to work with any combination of subsystems without requiring all dependencies.

Design Pattern

Each subsystem is expected to provide a registration function via adapters:

namespace kcenon::<subsystem>::di {
    VoidResult register_<subsystem>_services(service_container& container);
}

When adapters are implemented, they can be called within the conditional blocks.

Test Plan

• Build succeeds without warnings
• All existing tests pass (115/115)
• No runtime behavior changes (adapters not yet implemented)
• Code compiles with and without subsystem feature flags

Build Results

100% tests passed, 0 tests failed out of 115
Total Test time (real) = 50.81 sec

Breaking Changes

None - This is a backward-compatible enhancement.

Related Issues

Part of #314 (Epic: Consolidate cross-system infrastructure components)
Closes #317

Files Modified

• include/kcenon/common/di/unified_bootstrapper.h: Service registration implementation

Next Steps

After this PR:

1. Each subsystem team can implement their adapter's register_*_services() function
2. The bootstrapper will automatically integrate with available subsystems
3. No changes to unified_bootstrapper will be needed for future subsystem additions