ci: add macOS DMG build workflow

Add GitHub Actions workflow for building macOS DMG package
with Qt6 using aqtinstall and macdeployqt.

Author: nashsu

.github/workflows/build-dmg-qt6-macos.yml

@@ -0,0 +1,149 @@
+name: Build macOS DMG (Qt6, Universal)
+
+on:
+  push:
+    tags:
+      - "*"
+  workflow_dispatch:
+    inputs:
+      branch:
+        description: 'Checkout branch'
+        required: false
+        default: 'dev'
+      tag:
+        description: 'Checkout tag'
+        required: false
+
+permissions:
+  contents: write
+
+jobs:
+  build-omodsim:
+    name: Build OpenModSim macOS DMG version '${{ github.event.inputs.tag || github.event.inputs.branch || github.ref_name }}' with Qt6
+    runs-on: macos-latest
+
+    env:
+      QT_VERSION: "6.9.3"
+      QT_HOST: "mac"
+      QT_TARGET: "desktop"
+      QT_ARCH: "clang_64"
+      QT_INSTALL_DIR: "${{ github.workspace }}/Qt"
+      CMAKE_GENERATOR: "Ninja"
+      BUILD_TYPE: "Release"
+      DMG_PACKAGE_NAME: "qt6-omodsim"
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.inputs.tag || github.event.inputs.branch || github.ref_name }}
+
+      - name: Determine ref_type and ref_name
+        run: |
+          if [ "${{ github.ref_type }}" = "tag" ] || [ -n "${{ github.event.inputs.tag }}" ]; then
+            REF_TYPE="tags"
+            if [ -n "${{ github.event.inputs.tag }}" ]; then
+              REF_NAME="${{ github.event.inputs.tag }}"
+            else
+              REF_NAME="${{ github.ref_name }}"
+            fi
+          else
+            REF_TYPE="heads"
+            REF_NAME="${{ github.ref_name }}"
+          fi
+          echo "REF_TYPE=$REF_TYPE" >> $GITHUB_ENV
+          echo "REF_NAME=$REF_NAME" >> $GITHUB_ENV
+
+      - name: Extract version from CMakeLists.txt
+        run: |
+          FULL_VERSION=$(grep -oE 'VERSION\s+[0-9]+\.[0-9]+\.[0-9]+' src/CMakeLists.txt | grep -oE '[0-9]+\.[0-9]+\.[0-9]+')
+
+          if [ "${GITHUB_REF_NAME}" = "dev" ] || [ "${{ github.event.inputs.branch }}" = "dev" ]; then
+            MAJOR_MINOR=$(echo "$FULL_VERSION" | cut -d. -f1,2)
+            APP_VERSION="${MAJOR_MINOR}~dev"
+          else
+            APP_VERSION="$FULL_VERSION"
+          fi
+
+          echo "APP_VERSION=$APP_VERSION" >> $GITHUB_ENV
+          echo "Extracted version: $APP_VERSION"
+
+      - name: Install dependencies
+        run: |
+          brew install ninja cmake
+
+      - name: Install Python (for aqtinstall)
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: Install aqtinstall
+        run: python -m pip install aqtinstall
+
+      - name: Download Qt
+        run: |
+          mkdir -p ${{ env.QT_INSTALL_DIR }}
+          aqt install-qt \
+            ${{ env.QT_HOST }} \
+            ${{ env.QT_TARGET }} \
+            ${{ env.QT_VERSION }} \
+            ${{ env.QT_ARCH }} \
+            -m qt5compat qtpdf qtserialport qtserialbus \
+            -O ${{ env.QT_INSTALL_DIR }}
+
+      - name: Add Qt to PATH
+        run: echo "${{ env.QT_INSTALL_DIR }}/${{ env.QT_VERSION }}/macos/bin" >> $GITHUB_PATH
+
+      - name: Set BUILD_DIR
+        run: echo "BUILD_DIR=build-omodsim-Qt_${{ env.QT_VERSION }}_clang_64-${{ env.BUILD_TYPE }}" >> $GITHUB_ENV
+
+      - name: Configure project
+        run: |
+          cmake src -B ${{ env.BUILD_DIR }} \
+            -G "${{ env.CMAKE_GENERATOR }}" \
+            -DCMAKE_BUILD_TYPE=${{ env.BUILD_TYPE }} \
+            -DCMAKE_PREFIX_PATH=${{ env.QT_INSTALL_DIR }}/${{ env.QT_VERSION }}/macos \
+            -DUSE_QT6=ON
+
+      - name: Build
+        run: cmake --build ${{ env.BUILD_DIR }} --config ${{ env.BUILD_TYPE }} --parallel
+
+      - name: Deploy Qt dependencies using macdeployqt
+        run: |
+          "${{ env.QT_INSTALL_DIR }}/${{ env.QT_VERSION }}/macos/bin/macdeployqt" \
+            "${{ env.BUILD_DIR }}/omodsim.app" \
+            -always-overwrite
+
+      - name: Copy docs into app bundle
+        run: |
+          mkdir -p "${{ env.BUILD_DIR }}/omodsim.app/Contents/Resources/docs"
+          cp -R "${{ env.BUILD_DIR }}/docs/"* "${{ env.BUILD_DIR }}/omodsim.app/Contents/Resources/docs/"
+
+      - name: Create DMG
+        run: |
+          DMG_NAME="${{ env.DMG_PACKAGE_NAME }}_${{ env.APP_VERSION }}_macos.dmg"
+          echo "DMG_NAME=$DMG_NAME" >> $GITHUB_ENV
+
+          hdiutil create -volname "Open ModSim ${{ env.APP_VERSION }}" \
+            -srcfolder "${{ env.BUILD_DIR }}/omodsim.app" \
+            -ov -format UDZO \
+            "$DMG_NAME"
+
+      - name: Upload DMG
+        uses: actions/upload-artifact@v4
+        if: success()
+        with:
+          name: ${{ env.DMG_NAME }}
+          path: ${{ env.DMG_NAME }}
+
+      - name: Create or update GitHub Release and upload DMG
+        if: success() && github.event_name == 'push' && github.ref_type == 'tag'
+        uses: softprops/action-gh-release@v2
+        with:
+          draft: true
+          tag_name: ${{ github.ref_name }}
+          name: Open ModSim ${{ env.APP_VERSION }}
+          files: |
+            ${{ env.DMG_NAME }}
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}