Fix permissions

Dockerfile

@@ -11,6 +11,20 @@ RUN git clone https://github.com/clusterofstars-sg/TinyHackathon.git /app
 # Set working directory
 WORKDIR /app
 
+# Create a non-root user to run the application
+RUN useradd -m appuser
+RUN chown -R appuser:appuser /app
+
+# Set environment variable for uv to use a writable directory
+ENV UV_CACHE_DIR=/app/.cache/uv
+
+# Create and set permissions for the cache directory
+RUN mkdir -p /app/.cache/uv
+RUN chown -R appuser:appuser /app/.cache
+
+# Switch to the non-root user
+USER appuser
+
 # Install uv
 RUN pip install uv