Build and run pkg-config examples in generic CI on Linux

Adds a step after the existing example tests that discovers the
installed f3d.pc/f3d_c_api.pc and VTK's lib directory, then builds
and runs both pkg-config examples with the sdk component's .pc
files, mirroring what a real downstream user would do.

Author: AnikethTS

.github/actions/generic-ci/action.yml

@@ -378,6 +378,21 @@ runs:
       working-directory: ${{github.workspace}}
       run: ctest --test-dir build_examples --no-tests=error -C Release -VV
 
+    # These use pkg-config directly instead of find_package(f3d), so they are built
+    # separately from the other examples with a plain Makefile instead of CMake.
+    - name: Build and run pkg-config examples
+      if: runner.os == 'Linux' && inputs.static_label == 'no-static'
+      shell: bash
+      working-directory: ${{github.workspace}}
+      run: |
+        F3D_PKGCONFIG_DIR=$(dirname "$(find $(pwd)/install -name 'f3d.pc')")
+        VTK_LIB_DIR=$(dirname "$(find $(pwd)/dependencies/install -name 'libvtkCommonCore.so*' | head -1)")
+        export PKG_CONFIG_PATH=$F3D_PKGCONFIG_DIR
+        for lang in c cpp; do
+          make -C source/examples/libf3d/$lang/pkgconfig LDFLAGS="-Wl,-rpath-link,$VTK_LIB_DIR"
+          LD_LIBRARY_PATH=$VTK_LIB_DIR source/examples/libf3d/$lang/pkgconfig/check-engine-pkgconfig
+        done
+
     - name: Install optional component f3d plugins
       shell: bash
       working-directory: ${{github.workspace}}/build