Add GitHub Actions CI/CD workflow

Co-authored-by: sonnyt <183387+sonnyt@users.noreply.github.com>

Author: Copilot

.github/workflows/ci.yml

@@ -0,0 +1,78 @@
+name: CI
+
+on:
+  push:
+    branches: [ main, develop ]
+  pull_request:
+    branches: [ main, develop ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
+
+    steps:
+    - uses: actions/checkout@v4
+    
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v5
+      with:
+        python-version: ${{ matrix.python-version }}
+    
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install -e .
+        pip install -r requirements-dev.txt
+    
+    - name: Run tests
+      run: |
+        python -m pytest tests/ -v --tb=short
+    
+    - name: Check package can be imported
+      run: |
+        python -c "from bundleup import BundleUp; print('✓ Package imports successfully')"
+
+  lint:
+    runs-on: ubuntu-latest
+    
+    steps:
+    - uses: actions/checkout@v4
+    
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: '3.12'
+    
+    - name: Check Python syntax
+      run: |
+        python -m py_compile bundleup/*.py bundleup/unify/*.py tests/*.py
+
+  build:
+    runs-on: ubuntu-latest
+    needs: [test, lint]
+    
+    steps:
+    - uses: actions/checkout@v4
+    
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: '3.12'
+    
+    - name: Install build dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install build
+    
+    - name: Build package
+      run: |
+        python -m build
+    
+    - name: Upload artifacts
+      uses: actions/upload-artifact@v4
+      with:
+        name: dist
+        path: dist/