fix: include README.md in Docker build for package metadata

Dockerfile

@@ -18,7 +18,7 @@ RUN apt-get update && apt-get install -y gcc g++ \
     && rm -rf /var/lib/apt/lists/*
 
 # Copy project metadata and backend source for package installation
-COPY pyproject.toml .
+COPY pyproject.toml README.md ./
 COPY backend ./backend/
 RUN pip install --no-cache-dir .