Fix macOS build and improve Python wheel configuration

macOS fixes:
- Make PCL installation optional on macOS (can be problematic)
- Allow build to continue if PCL fails to install

Python wheel fixes:
- Add CMAKE_POSITION_INDEPENDENT_CODE=ON for shared library builds
- Keep bundled dependencies approach for wheel builds

This should resolve macOS C++ build failures while maintaining
successful Ubuntu builds.

Author: LimHyungTae

.github/workflows/ci-cpp.yml

@@ -66,8 +66,9 @@ jobs:
             tbb \
             lz4 \
             flann \
-            pcl \
             git
+          # PCL can be problematic on macOS, try to install it separately
+          brew install pcl || echo "PCL installation failed, will use bundled version"
 
       - name: Setup MSVC (Windows)
         if: runner.os == 'Windows'

python/pyproject.toml

@@ -51,5 +51,6 @@ cmake.args = [
     "-DUSE_SYSTEM_ROBIN=OFF"
 ]
 cmake.define = {
-    CMAKE_CXX_STANDARD = "17"
+    CMAKE_CXX_STANDARD = "17",
+    CMAKE_POSITION_INDEPENDENT_CODE = "ON"
 }