fix: enable unbuffered Python output in container

Without PYTHONUNBUFFERED=1, Python buffers stdout causing
podman logs to show no output.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Containerfile

@@ -5,4 +5,5 @@ WORKDIR /app
 RUN pip install --no-cache-dir maxminddb>=2.0 PySocks>=1.7.1
 
 ENV PYTHONPATH=/app/src
+ENV PYTHONUNBUFFERED=1
 ENTRYPOINT ["python", "-m", "derp"]