Add aarch64 wheel build to CI workflow

- Add build-wheels-aarch64 job using native ubuntu-24.04-arm runner
- Add workflow_dispatch for manual triggering
- Add build/* branch pattern to push triggers for testing

Author: bghira

.github/workflows/ci.yml

@@ -2,9 +2,10 @@ name: CI
 
 on:
   push:
-    branches: [ main, develop ]
+    branches: [ main, develop, 'build/*' ]
   pull_request:
     branches: [ main ]
+  workflow_dispatch:
 
 env:
   CARGO_TERM_COLOR: always
@@ -375,3 +376,78 @@ jobs:
       with:
         name: wheels-${{ matrix.os }}
         path: dist/
+
+  build-wheels-aarch64:
+    name: Build wheels (Linux aarch64)
+    runs-on: ubuntu-24.04-arm
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Install OpenCV and LLVM dependencies
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y pkg-config clang libclang-dev llvm-dev wget cmake build-essential
+        # Install LLVM 18 which has the proper libclang.so symlink
+        sudo apt-get install -y llvm-18 llvm-18-dev llvm-18-tools libclang1-18 libclang-cpp18
+        # Set environment variables for LLVM 18
+        echo "LIBCLANG_PATH=/usr/lib/llvm-18/lib" >> $GITHUB_ENV
+        echo "LLVM_CONFIG_PATH=/usr/bin/llvm-config-18" >> $GITHUB_ENV
+        echo "LD_LIBRARY_PATH=/usr/lib/llvm-18/lib:$LD_LIBRARY_PATH" >> $GITHUB_ENV
+
+        # Build OpenCV 4.12 from source
+        echo "Building OpenCV 4.12 from source..."
+        cd /tmp
+        wget -q https://github.com/opencv/opencv/archive/4.12.0.tar.gz
+        tar -xzf 4.12.0.tar.gz
+        cd opencv-4.12.0
+        mkdir build
+        cd build
+        cmake \
+          -DCMAKE_BUILD_TYPE=RELEASE \
+          -DCMAKE_INSTALL_PREFIX=/usr/local \
+          -DWITH_CUDA=OFF \
+          -DWITH_OPENGL=OFF \
+          -DWITH_OPENCL=OFF \
+          -DWITH_TBB=OFF \
+          -DWITH_IPP=OFF \
+          -DWITH_1394=OFF \
+          -DWITH_V4L=OFF \
+          -DWITH_GTK=OFF \
+          -DBUILD_TESTS=OFF \
+          -DBUILD_PERF_TESTS=OFF \
+          -DBUILD_EXAMPLES=OFF \
+          -DBUILD_opencv_python2=OFF \
+          -DBUILD_opencv_python3=OFF \
+          -DBUILD_opencv_java=OFF \
+          -DOPENCV_GENERATE_PKGCONFIG=ON \
+          ..
+        make -j$(nproc)
+        sudo make install
+        sudo ldconfig
+
+        # Set OpenCV environment variables
+        echo "PKG_CONFIG_PATH=/usr/local/lib/pkgconfig:$PKG_CONFIG_PATH" >> $GITHUB_ENV
+        echo "LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH" >> $GITHUB_ENV
+
+    - name: Set up Python
+      uses: actions/setup-python@v4
+      with:
+        python-version: 3.11
+
+    - name: Install Rust toolchain
+      uses: dtolnay/rust-toolchain@master
+      with:
+        toolchain: 1.89
+
+    - name: Install maturin
+      run: pip install maturin[patchelf]
+
+    - name: Build wheels
+      run: maturin build --release --out dist --no-default-features --features python-bindings,simd,opencv
+
+    - name: Upload wheels
+      uses: actions/upload-artifact@v4
+      with:
+        name: wheels-linux-aarch64
+        path: dist/