fix: Update Dockerfile for Hugging Face /tmp directories and env vars

Dockerfile

@@ -15,11 +15,18 @@ RUN pip install --no-cache-dir -r requirements.txt
 # Copy application code
 COPY . .
 
-# Create data directories
-RUN mkdir -p data chroma_db
+# Create writable directories in /tmp (Hugging Face only allows writes to /tmp)
+RUN mkdir -p /tmp/data /tmp/chroma_db /tmp/code_chatbot_extracted
 
 # Expose Streamlit port
 EXPOSE 7860
 
+# Environment variables for Hugging Face Spaces
+# Note: Actual API keys should be set in Hugging Face Space Secrets, not here
+ENV STREAMLIT_SERVER_PORT=7860
+ENV STREAMLIT_SERVER_ADDRESS=0.0.0.0
+ENV STREAMLIT_SERVER_HEADLESS=true
+ENV STREAMLIT_BROWSER_GATHER_USAGE_STATS=false
+
 # Run Streamlit
 CMD ["streamlit", "run", "app.py", "--server.port=7860", "--server.address=0.0.0.0"]