Improve logging; avoid build-time secret

Dockerfile

@@ -1,9 +1,5 @@
 FROM python:3.10-slim
 
-# Accept API key as build arg
-ARG ANTHROPIC_API_KEY
-ENV ANTHROPIC_API_KEY=$ANTHROPIC_API_KEY
-
 WORKDIR /app
 
 # Install system dependencies
@@ -21,8 +17,9 @@ COPY . .
 # Expose port 7860 (Gradio default)
 EXPOSE 7860
 
-# Set environment variable for Gradio
-ENV GRADIO_SERVER_NAME="0.0.0.0"
+# Runtime env (logging + Gradio bind)
+ENV PYTHONUNBUFFERED=1 \
+    GRADIO_SERVER_NAME="0.0.0.0"
 
 # Run the app
-CMD ["python", "app.py"]
+CMD ["python", "-u", "app.py"]