Fix Dockerfile: preserve src/python directory structure for pyproject.toml

pyproject.toml has packages.find.where = ['src/python'], so the Docker
build context needs src/python/ to exist. Previously COPY flattened it.

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

Author: apartsin

Dockerfile

@@ -1,7 +1,7 @@
 FROM python:3.12-slim
 WORKDIR /app
-COPY src/python/ ./
 COPY pyproject.toml ./
+COPY src/python/ ./src/python/
 RUN pip install . && pip install pyyaml>=6.0
 EXPOSE 8080
 ENTRYPOINT ["python", "-m", "modelmesh.proxy"]