feat: add Django backend skeleton

infra/docker/backend/Dockerfile

@@ -5,18 +5,17 @@ ENV PYTHONUNBUFFERED=1
 
 WORKDIR /app
 
-RUN pip install --no-cache-dir \
-    "Django==5.2.3" \
-    "djangorestframework==3.16.0" \
-    "gunicorn==23.0.0" \
-    "psycopg[binary]==3.2.9"
-
 RUN useradd --create-home --shell /usr/sbin/nologin appuser
 
-COPY placeholder_wsgi.py /app/placeholder_wsgi.py
+COPY requirements/backend.txt /app/requirements/backend.txt
+RUN pip install --no-cache-dir -r /app/requirements/backend.txt
+
+COPY backend/ /app/backend/
+
+WORKDIR /app/backend
 
 USER appuser
 
 EXPOSE 8000
 
-CMD ["gunicorn", "--bind", "0.0.0.0:8000", "placeholder_wsgi:application"]
+CMD ["gunicorn", "--bind", "0.0.0.0:8000", "azionelab.wsgi:application"]

infra/docker/backend/placeholder_wsgi.py

@@ -1,10 +0,0 @@
-def application(environ, start_response):
-    body = b"AzioneLab backend placeholder\n"
-    start_response(
-        "503 Service Unavailable",
-        [
-            ("Content-Type", "text/plain; charset=utf-8"),
-            ("Content-Length", str(len(body))),
-        ],
-    )
-    return [body]