ci: add GitHub Actions workflows

- ci.yml: Tests on Python 3.9-3.12, Linux/Windows/macOS
- ci.yml: Linting with Ruff, Black, MyPy
- ci.yml: Build and package verification
- publish.yml: Auto-publish to PyPI on release

Author: medeirosdev

.github/workflows/ci.yml

@@ -0,0 +1,96 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+        python-version: ["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 ".[dev]"
+
+      - name: Run tests
+        run: pytest --tb=short -q
+
+      - name: Run tests with coverage
+        if: matrix.os == 'ubuntu-latest' && matrix.python-version == '3.11'
+        run: pytest --cov=trueentropy --cov-report=xml
+
+      - name: Upload coverage
+        if: matrix.os == 'ubuntu-latest' && matrix.python-version == '3.11'
+        uses: codecov/codecov-action@v3
+        with:
+          file: ./coverage.xml
+          fail_ci_if_error: false
+
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install ruff black mypy
+
+      - name: Run Ruff
+        run: ruff check src/
+
+      - name: Run Black
+        run: black --check src/
+
+      - name: Install for type checking
+        run: pip install -e ".[dev]"
+
+      - name: Run MyPy
+        run: mypy src/trueentropy --ignore-missing-imports
+        continue-on-error: true
+
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - name: Install build tools
+        run: pip install build twine
+
+      - name: Build package
+        run: python -m build
+
+      - name: Check package
+        run: twine check dist/*
+
+      - name: Upload artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: dist
+          path: dist/

.github/workflows/publish.yml

@@ -0,0 +1,29 @@
+name: Publish to PyPI
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    environment: pypi
+    permissions:
+      id-token: write
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - name: Install build tools
+        run: pip install build
+
+      - name: Build package
+        run: python -m build
+
+      - name: Publish to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1