ci: add Python 3.12 GitHub Actions build workflow (AG-02)

Author: OgeonX-Ai

.github/workflows/ci.yml

@@ -0,0 +1,23 @@
+name: CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python 3.12
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+
+      - name: Install test runner
+        run: pip install pytest
+
+      - name: Run static contract tests
+        run: python -m pytest tests/test_phase5_ui_contract.py tests/test_phase5_operator_views.py -v