feat(cli): install local embedding runtime on demand

.github/docker/chatlab-cli.Dockerfile

@@ -3,11 +3,13 @@
 FROM node:24-bookworm-slim
 
 ARG CHATLAB_VERSION
+ENV CHATLAB_LOCAL_EMBEDDING_RUNTIME_DIR=/opt/chatlab/local-embedding
 
 RUN test -n "$CHATLAB_VERSION" \
     && apt-get update \
     && apt-get install --yes --no-install-recommends g++ make python3 \
     && npm install --global --omit=dev "chatlab-cli@${CHATLAB_VERSION}" \
+    && CHATLAB_SKIP_UPDATE_CHECK=1 chatlab runtime install local-embedding \
     && npm cache clean --force \
     && apt-get purge --yes --auto-remove g++ make python3 \
     && rm -rf /var/lib/apt/lists/*