Update code to use environment variables and improve error handling

Dockerfile

@@ -9,6 +9,9 @@ RUN apt-get update && apt-get install -y \
     software-properties-common \
     && rm -rf /var/lib/apt/lists/*
 
+# Create a non-root user
+RUN useradd -m -u 1000 chainlit_user
+
 # Copy requirements first for better caching
 COPY requirements.txt /code/requirements.txt
 RUN pip install --no-cache-dir -r requirements.txt
@@ -16,10 +19,23 @@ RUN pip install --no-cache-dir -r requirements.txt
 # Copy the rest of the application
 COPY . /code/
 
+# Create necessary directories and set permissions
+RUN mkdir -p /code/.files && \
+    mkdir -p /code/.chainlit && \
+    chown -R chainlit_user:chainlit_user /code && \
+    chmod -R 755 /code && \
+    chmod -R 777 /code/.files && \
+    chmod -R 777 /code/.chainlit
+
 # Set environment variables
 ENV HOST=0.0.0.0
 ENV PORT=7860
 ENV PYTHONPATH=/code
+ENV OPENAI_API_KEY=${OPENAI_API_KEY}
+ENV PYTHONUNBUFFERED=1
+
+# Switch to non-root user
+USER chainlit_user
 
 # Command to run the application
 CMD chainlit run app.py --host $HOST --port $PORT