Part of kcenon/common_system#454

What

The project vcpkg.json defines a grpc feature (gRPC + protobuf), but the overlay port vcpkg-ports/kcenon-monitoring-system/vcpkg.json does not expose it. Consumers installing via the overlay port cannot enable gRPC-based metrics export.

• Current: Port has logging and network features only
• Expected: Port also exposes a grpc feature matching the project manifest
• Scope: vcpkg-ports/kcenon-monitoring-system/vcpkg.json and portfile.cmake

Feature Comparison

Why

• The project CMakeLists.txt supports gRPC monitoring via find_package(gRPC CONFIG QUIET) at line 343
• The portfile already passes CMake options based on features but has no grpc feature to trigger them
• Consumers wanting gRPC-based OTLP/Prometheus monitoring cannot enable it through the vcpkg overlay port
• Feature parity between the project manifest and the port ensures consistent behavior

Where

• vcpkg-ports/kcenon-monitoring-system/vcpkg.json — features section
• vcpkg-ports/kcenon-monitoring-system/portfile.cmake — feature check and CMake option passthrough

How

Technical Approach

1. Add grpc feature to vcpkg-ports/kcenon-monitoring-system/vcpkg.json:

   "grpc": {
       "description": "Enable gRPC-based metrics export (OTLP, Prometheus)",
       "dependencies": [
           { "name": "grpc", "version>=": "1.51.1" },
           { "name": "protobuf", "version>=": "3.21.0" }
       ]
   }

2. Add feature passthrough in portfile.cmake:

   vcpkg_check_features(OUT_PREFIX MONITORING
       FEATURES
           logging WITH_LOGGER
           network WITH_NETWORK
           grpc    WITH_GRPC
   )
   # ... in vcpkg_cmake_configure OPTIONS:
   -DMONITORING_WITH_GRPC=${MONITORING_WITH_GRPC}

Acceptance Criteria

• Port vcpkg.json includes grpc feature with correct dependencies
• portfile.cmake passes MONITORING_WITH_GRPC flag based on feature
• vcpkg install kcenon-monitoring-system[grpc] builds with gRPC support
• Existing features (logging, network) are unaffected