Fix macOS linker error: replace pkg-config JsonCpp detection with CMake target linking

[Copilot]

On Apple Silicon macOS, pkg_check_modules(JSONCPP jsoncpp) resolves JSONCPP_LIBRARIES to the raw flag -ljsoncpp, which the macOS linker cannot resolve. Homebrew-installed JsonCpp exposes a proper CMake config package with the jsoncpp_lib target.

Changes

• JsonCpp detection — replace the pkg_check_modules + find_package fallback chain with a single find_package(jsoncpp CONFIG QUIET)
• Linking — remove ${JSONCPP_LIBRARIES} from both ailee_node and ailee_adapters; link via jsoncpp_lib target inside a if(jsoncpp_FOUND) guard instead
• Include dirs — remove ${JSONCPP_INCLUDE_DIRS} from global include_directories; the jsoncpp_lib target propagates its own includes transitively
• Compile definitions — consolidate AILEE_HAS_JSONCPP=1 into the same if(jsoncpp_FOUND) block, removing the now-redundant if(JSONCPP_FOUND OR jsoncpp_FOUND) checks

Before:

pkg_check_modules(JSONCPP jsoncpp)          # sets JSONCPP_LIBRARIES = -ljsoncpp on macOS
if(NOT JSONCPP_FOUND)
    find_package(jsoncpp QUIET)
    ...
endif()
# later:
target_link_libraries(ailee_node PRIVATE ... ${JSONCPP_LIBRARIES} ...)  # ld: library 'jsoncpp' not found

After:

find_package(jsoncpp CONFIG QUIET)
# later:
if(jsoncpp_FOUND)
    target_link_libraries(ailee_node PRIVATE jsoncpp_lib)
    target_compile_definitions(ailee_node PRIVATE AILEE_HAS_JSONCPP=1)
endif()

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[chatgpt-codex-connector]

You have reached your Codex usage limits for code reviews. You can see your limits in the Codex usage dashboard.

[Copilot]

Pull request overview

This PR fixes a macOS linker error where pkg-config resolves JsonCpp to an unresolvable -ljsoncpp flag. The solution replaces the pkg-config detection with CMake's config-based package discovery, which provides proper imported targets with transitive include and link dependencies.

Changes:

• Simplified JsonCpp detection to use find_package(jsoncpp CONFIG QUIET) instead of a pkg-config + fallback chain
• Replaced raw library flag linking (${JSONCPP_LIBRARIES}) with CMake target linking (jsoncpp_lib) for both ailee_node and ailee_adapters
• Consolidated compile definitions and linking into single conditional blocks guarded by jsoncpp_FOUND

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.