Add comprehensive GitHub Actions CI/CD workflow

Features:
- Test matrix across Python 3.9, 3.10, 3.11, 3.12
- Cross-platform testing: Ubuntu, Windows, macOS
- Dependency caching for faster builds
- System dependencies (FFmpeg) installation
- Coverage reporting on Ubuntu Python 3.12
- Parallel execution with fail-fast disabled
- Triggers on push/PR to master and dev branches

The workflow runs 12 parallel jobs (4 Python versions × 3 OS) to ensure
comprehensive compatibility testing across all supported environments.

Also added importlib_metadata fallback dependency for Python < 3.8
compatibility in requirements.txt.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: jeremymanning

.github/workflows/test.yml

@@ -0,0 +1,78 @@
+name: Tests
+
+on:
+  push:
+    branches: [ master, dev ]
+  pull_request:
+    branches: [ master, dev ]
+
+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@v4
+      with:
+        python-version: ${{ matrix.python-version }}
+        
+    - name: Cache pip dependencies
+      uses: actions/cache@v3
+      with:
+        path: ~/.cache/pip
+        key: ${{ runner.os }}-pip-${{ matrix.python-version }}-${{ hashFiles('**/requirements.txt') }}
+        restore-keys: |
+          ${{ runner.os }}-pip-${{ matrix.python-version }}-
+          ${{ runner.os }}-pip-
+          
+    - name: Install system dependencies (Ubuntu)
+      if: matrix.os == 'ubuntu-latest'
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y ffmpeg
+        
+    - name: Install system dependencies (macOS)
+      if: matrix.os == 'macos-latest'
+      run: |
+        brew install ffmpeg
+        
+    - name: Install system dependencies (Windows)
+      if: matrix.os == 'windows-latest'
+      run: |
+        choco install ffmpeg
+      continue-on-error: true
+        
+    - name: Install Python dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install pytest pytest-cov
+        pip install -r requirements.txt
+        
+    - name: Install package in development mode
+      run: |
+        pip install -e .
+        
+    - name: Run pytest
+      run: |
+        pytest -v --tb=short
+        
+    - name: Run pytest with coverage (Ubuntu Python 3.12 only)
+      if: matrix.os == 'ubuntu-latest' && matrix.python-version == '3.12'
+      run: |
+        pytest --cov=hypertools --cov-report=xml --cov-report=term-missing
+        
+    - name: Upload coverage to Codecov (Ubuntu Python 3.12 only)
+      if: matrix.os == 'ubuntu-latest' && matrix.python-version == '3.12'
+      uses: codecov/codecov-action@v3
+      with:
+        file: ./coverage.xml
+        flags: unittests
+        name: codecov-umbrella
+        fail_ci_if_error: false

notes/github_actions_info.md

@@ -0,0 +1,43 @@
+# GitHub Actions CI/CD Setup
+
+## Test Matrix
+The GitHub Actions workflow (`/.github/workflows/test.yml`) runs comprehensive tests on:
+
+### Python Versions
+- Python 3.9
+- Python 3.10  
+- Python 3.11
+- Python 3.12
+
+### Operating Systems
+- Ubuntu Latest (Linux)
+- Windows Latest
+- macOS Latest
+
+### Features
+- **Dependency caching**: Pip cache is used to speed up builds
+- **System dependencies**: FFmpeg is installed for animation support
+- **Coverage reporting**: Coverage is collected on Ubuntu Python 3.12 and uploaded to Codecov
+- **Matrix strategy**: Tests run in parallel across all combinations (12 total jobs)
+- **Fail-fast disabled**: All combinations run even if one fails
+
+## Triggers
+- Push to `master` or `dev` branches
+- Pull requests to `master` or `dev` branches
+
+## Badge
+Add this badge to README.md to show build status:
+```markdown
+[![Tests](https://github.com/ContextLab/hypertools/workflows/Tests/badge.svg)](https://github.com/ContextLab/hypertools/actions)
+```
+
+## Local Testing
+To run the same tests locally:
+```bash
+pytest -v --tb=short
+```
+
+For coverage:
+```bash
+pytest --cov=hypertools --cov-report=xml --cov-report=term-missing
+```

requirements.txt

@@ -8,3 +8,4 @@ numpy>=2.0.0
 umap-learn>=0.5.5
 requests>=2.31.0
 ipympl>=0.9.3
+importlib_metadata>=1.0.0; python_version < "3.8"