ci: add github actions workflow

Add CI/CD pipeline with GitHub Actions that:
- Runs tests with pytest
- Performs linting with flake8, black, and isort
- Uploads coverage reports
- Automatically creates releases based on semantic versioning

🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>

Author: jonathan-irvin

.github/workflows/ci.yml

@@ -0,0 +1,78 @@
+name: CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["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 }}
+        cache: 'pip'
+    
+    - name: Install Poetry
+      uses: snok/install-poetry@v1
+      with:
+        version: 1.8.3
+        virtualenvs-create: true
+        virtualenvs-in-project: true
+    
+    - name: Cache Poetry dependencies
+      uses: actions/cache@v4
+      with:
+        path: .venv
+        key: ${{ runner.os }}-poetry-${{ hashFiles('**/poetry.lock') }}
+    
+    - name: Install dependencies
+      run: poetry install
+    
+    - name: Lint with flake8
+      run: |
+        poetry run flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
+        poetry run flake8 . --count --exit-zero --max-complexity=10 --max-line-length=88 --statistics
+    
+    - name: Format check with black
+      run: poetry run black --check .
+    
+    - name: Import sorting check with isort
+      run: poetry run isort --check .
+    
+    - name: Test with pytest
+      run: poetry run pytest --cov=src
+    
+    - name: Upload coverage to Codecov
+      uses: codecov/codecov-action@v4
+      with:
+        token: ${{ secrets.CODECOV_TOKEN }}
+        fail_ci_if_error: false
+
+  release:
+    needs: test
+    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+    runs-on: ubuntu-latest
+    concurrency: release
+    permissions:
+      id-token: write
+      contents: write
+
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+    
+    - name: Python Semantic Release
+      uses: python-semantic-release/python-semantic-release@master
+      with:
+        github_token: ${{ secrets.GITHUB_TOKEN }}