Fix: Install system dependencies as root before switching user

Dockerfile

@@ -1,6 +1,9 @@
 # Get a distribution that has uv already installed
 FROM ghcr.io/astral-sh/uv:python3.13-bookworm-slim
 
+# Install required system dependencies for building packages (as root)
+RUN apt-get update && apt-get install -y gcc g++ python3-dev
+
 # Add user - this is the user that will run the app
 RUN useradd -m -u 1000 user
 USER user
@@ -14,9 +17,6 @@ ENV UVICORN_WS_PROTOCOL=websockets
 # Set the working directory
 WORKDIR $HOME/app
 
-# Install required system dependencies for building packages
-RUN apt-get update && apt-get install -y gcc g++ python3-dev
-
 # Copy the app to the container
 COPY --chown=user . $HOME/app