Set up CI with GitHub Actions (separate fast and slow test jobs)

[thomaspinder]

Overview

Set up a GitHub Actions CI workflow that runs on push and PR to main.

Proposed Workflow

Fast Job (runs on every push/PR)

• Matrix: Python 3.10, 3.11, 3.12, 3.13, 3.14
• Steps:
  1. uv sync
  2. ruff check . && ruff format --check .
  3. uv run ty check
  4. uv run pytest -m "not slow" --cov
• Target: < 2 minutes

Slow Job (runs on PR to main only, or manual trigger)

• Matrix: Python 3.12 only (to save CI minutes)
• Steps:
  1. uv sync
  2. uv run pytest -m slow --cov -v
• Target: < 10 minutes
• Note: Must use cores=1 for MCMC tests (see Fix parallel MCMC sampling segfault (cores=1 workaround) #2)

Docs Job

• Single Python version (3.12)
• Steps:
  1. uv sync
  2. mkdocs build --strict

Configuration Needed

• Add @pytest.mark.slow marker to pyproject.toml if not already present
• Ensure all MCMC tests are marked with @pytest.mark.slow
• Add codecov upload step to fast job
• Consider caching uv dependencies

Labels

ci, infrastructure