Add GitHub Actions CI (pyclawd check + golden)

Mirrors pydacefit's workflow: matrix over py3.10-3.12, installs the object-based
pydacefit from git (it is not on PyPI) before ezmodel, then runs pyclawd
doctor / check / golden. Triggers on push to main and on PRs.

Author: blankjul

.github/workflows/ci.yml

@@ -0,0 +1,45 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.10", "3.11", "3.12"]
+    env:
+      # ezmodel's .pyclawd/config.py leaves conda_env unset; CI has no conda, so
+      # point pyclawd at the runner's interpreter.
+      PYCLAWD_PYTHON: python
+    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 package, dev tools, and pyclawd
+        run: |
+          python -m pip install --upgrade pip
+          # ezmodel needs the object-based pydacefit (not on PyPI); install it from
+          # git FIRST so it satisfies the dependency before ezmodel is installed.
+          pip install "git+https://github.com/msu-coinlab/pydacefit.git@main"
+          pip install -e .
+          # pin the quality tools so the gate is reproducible across runs
+          pip install "ruff==0.15.18" "mypy==2.1.0" "pytest==9.1.0" pytest-xdist pytest-cov
+          pip install "git+https://github.com/anyoptimization/pyclawd.git"
+
+      - name: Environment health check
+        run: pyclawd doctor
+
+      - name: Quality gate (format, lint, typecheck, descriptions, tests)
+        run: pyclawd check
+
+      - name: Behavior oracle (golden baselines)
+        run: pyclawd golden