chore(.github): add Django CI workflow

- New Features
  - Added CI pipeline that runs on push and pull‑request to main and develop, including PostgreSQL service for integration tests.  - Enhancements
  - Integrated linting (ruff), formatting check, migration validation, and security scanning with Django’s --deploy flag.
- Bug Fixes
  - (none)

.github/workflows/ci.yml

@@ -0,0 +1,109 @@
+name: Django CI
+
+on:
+  push:
+    branches: [ main, develop ]
+  pull_request:
+    branches: [ main, develop ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.12", "3.13"]
+
+    services:
+      postgres:
+        image: postgres:15
+        env:
+          POSTGRES_USER: postgres
+          POSTGRES_PASSWORD: postgres
+          POSTGRES_DB: test_db
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+        ports:
+          - 5432:5432
+
+    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 uv
+      uses: astral-sh/setup-uv@v4
+      with:
+        version: "latest"
+
+    - name: Install dependencies
+      run: uv sync
+
+    - name: Run linting
+      run: uv run ruff check .
+
+    - name: Format check
+      run: uv run ruff format --check .
+
+    - name: Set up PostgreSQL
+      env:
+        DB_NAME: test_db
+        DB_USER: postgres
+        DB_PASSWORD: postgres
+        DB_HOST: localhost
+        DB_PORT: 5432
+      run: |
+        echo "PostgreSQL is ready"
+
+    - name: Run Django tests
+      env:
+        DJANGO_SETTINGS_MODULE: core.settings.development
+        SECRET_KEY: test-secret-key-for-ci
+        ALLOWED_HOSTS: localhost
+        DB_NAME: test_db
+        DB_USER: postgres
+        DB_PASSWORD: postgres
+        DB_HOST: localhost
+        DB_PORT: 5432
+      run: |
+        uv run python manage.py check
+        uv run python manage.py test
+
+    - name: Check migrations
+      env:
+        DJANGO_SETTINGS_MODULE: core.settings.development
+        SECRET_KEY: test-secret-key-for-ci
+        ALLOWED_HOSTS: localhost
+        DB_NAME: test_db
+        DB_USER: postgres
+        DB_PASSWORD: postgres
+        DB_HOST: localhost
+        DB_PORT: 5432
+      run: |
+        uv run python manage.py makemigrations --check --dry-run
+
+  security:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: "3.13"
+
+    - name: Install uv
+      uses: astral-sh/setup-uv@v4
+      with:
+        version: "latest"
+
+    - name: Install dependencies
+      run: uv sync
+
+    - name: Run security check
+      run: uv run python manage.py check --deploy