build(client): use locked uv environment in launcher and Docker

s2s-client/Dockerfile

@@ -2,16 +2,24 @@
 # Serve backend APIs, the WebSocket proxy, and shared project documentation.
 # Run the React/Vite frontend separately; this image contains no browser UI.
 # HF Spaces (sdk: docker) routes traffic to $PORT, default 7860.
-FROM python:3.11-slim
+FROM python:3.12.14-slim
+
+COPY --from=ghcr.io/astral-sh/uv:0.12.5 /uv /uvx /bin/
+
+ENV UV_LINK_MODE=copy \
+    UV_PYTHON_DOWNLOADS=never \
+    PATH="/app/s2s-client/.venv/bin:$PATH"
 
 WORKDIR /app/s2s-client
 
-COPY s2s-client/requirements.txt .
-RUN pip install --no-cache-dir -r requirements.txt
+COPY s2s-client/pyproject.toml s2s-client/uv.lock ./
+RUN uv sync --locked --no-dev --no-install-project
 
-COPY s2s-client/ .
+COPY s2s-client/README.md s2s-client/server.py ./
+COPY s2s-client/s2s_client/ ./s2s_client/
 COPY docs/ /app/docs/
+RUN uv sync --locked --no-dev
 
 EXPOSE 7860
 
-CMD ["uvicorn", "server:app", "--host", "0.0.0.0", "--port", "7860"]
+CMD ["uvicorn", "s2s_client.main:app", "--host", "0.0.0.0", "--port", "7860"]