we are going to use docker instead

Dockerfile.test

@@ -0,0 +1,23 @@
+FROM python:3.11-slim
+
+# Install PostgreSQL binaries — required by pytest-postgresql to spawn ephemeral test databases
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends postgresql \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+
+# Copy requirements first so Docker can cache the install layer
+COPY backend/engine/requirements.txt backend/engine/requirements.txt
+COPY backend/app/requirements/requirements.txt backend/app/requirements/requirements.txt
+COPY test.requirements.txt test.requirements.txt
+
+RUN pip install --no-cache-dir \
+    -r backend/engine/requirements.txt \
+    -r backend/app/requirements/requirements.txt \
+    -r test.requirements.txt
+
+# Copy source
+COPY . .
+
+CMD ["pytest"]