Add simple FastAPI backend

backend/docker/Dockerfile

@@ -0,0 +1,12 @@
+FROM python:3.13.7-slim-bookworm
+
+WORKDIR /app
+
+# Copy requirements and install Python dependencies
+COPY ./requirements.txt ./
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Copy the app code and tests
+COPY ../src ./src
+
+CMD ["python", "src/main.py"]