ci(sdk): add pytest CI workflow for PRs and main pushes

Triggers on push/PR to main. Runs tests across Python 3.11, 3.12, 3.13
and adds ruff linting as a separate step.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -0,0 +1,29 @@
+name: Test
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ['3.11', '3.12', '3.13']
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install dependencies
+        run: pip install -e ".[test]"
+
+      - name: Run tests
+        run: python -m pytest tests/
+
+      - name: Lint
+        run: pip install ruff && ruff check molecule_agent/ molecule_plugin/