add docker files

Dockerfile

@@ -0,0 +1,31 @@
+# Slim Python image
+FROM python:3.12-slim
+
+ENV PYTHONDONTWRITEBYTECODE=1 \
+    PYTHONUNBUFFERED=1
+
+# System deps for pip & curl (for healthcheck)
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    build-essential curl \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+COPY . .
+
+# Ensure persistent folders exist
+RUN mkdir -p /app/instance /app/assets
+
+# Default port
+ENV FLET_PORT=8550
+
+EXPOSE 8550
+
+# Health check
+HEALTHCHECK --interval=30s --timeout=3s --retries=3 CMD curl -fsS http://127.0.0.1:8550/ || exit 1
+
+# Run entrypoint to create superuser and start the app
+ENTRYPOINT ["sh", "-c", "python main.py"]