ci: add GitHub Actions workflow to run tests on push and PR

Mirrors utec-py's test.yml — single Python 3.12 job that installs
requirements-test.txt and runs pytest with coverage. The coverage gate
(fail_under=85 in pyproject.toml) is enforced automatically.

Pins the integration runtime dep (utec_py_LF2b2w) into requirements-test.txt
so CI installs the same source the manifest pulls from at runtime.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: geofffranks

.github/workflows/test.yml

@@ -0,0 +1,21 @@
+name: Tests
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.12"]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+          cache: pip
+      - run: pip install -r requirements-test.txt
+      - run: pytest --cov --cov-report=term-missing

requirements-test.txt

@@ -4,3 +4,7 @@ pytest-cov>=5.0
 coverage[toml]>=7.4
 aioresponses>=0.7.6
 pytest-homeassistant-custom-component>=0.13.200
+
+# Integration runtime dep — must match manifest.json so the test suite
+# exercises the same utec_py source as the integration.
+utec_py_LF2b2w @ git+https://github.com/geofffranks/utec-py.git@main