Add GitHub Actions CI workflow for backend tests

.github/workflows/ci-backend.yml

@@ -0,0 +1,50 @@
+# .github/workflows/ci-backend.yml
+
+name: CI Backend
+
+on:
+  push:
+    paths:
+      - 'backend/**'
+  pull_request:
+    paths:
+      - 'backend/**'
+
+jobs:
+  build-and-test:
+    runs-on: ubuntu-22.04  # Specify the Ubuntu version explicitly
+
+    strategy:
+      matrix:
+        python-version: [3.12]
+
+    steps:
+      # Step 1: Checkout the repository
+      - name: Checkout Repository
+        uses: actions/checkout@v3
+
+      # Step 2: Set up Python environment with pip caching
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v4
+        with:
+          python-version: ${{ matrix.python-version }}
+          cache: 'pip'  # Enables pip caching
+
+      # Step 3: Install dependencies
+      - name: Install Dependencies
+        working-directory: backend
+        run: |
+          python -m pip install --upgrade pip
+          pip install -r requirements.lock
+
+      # Step 4: Run Linting with ruff
+      - name: Lint with ruff
+        working-directory: backend
+        run: |
+          ruff check api tests
+
+      # Step 5: Run Tests with Pytest and Coverage
+      - name: Run Pytest
+        working-directory: backend
+        run: |
+          pytest --cov=api --cov=tests --cov-report=xml