feat(build): implement multi-stage maintainer parent image and dual-tag cloud build

Dockerfile

@@ -1,21 +1,26 @@
-FROM docker.io/library/node:20-slim
+# --- STAGE 1: Base Runtime ---
+FROM docker.io/library/node:20-slim AS base
 
-ARG SANDBOX_NAME="gemini-cli-sandbox"
 ARG CLI_VERSION_ARG
-ENV SANDBOX="$SANDBOX_NAME"
 ENV CLI_VERSION=$CLI_VERSION_ARG
 
-# install minimal set of packages, then clean up
 RUN apt-get update && apt-get install -y --no-install-recommends \
   python3 \
-  make \
-  g++ \
-  man-db \
   curl \
   dnsutils \
   less \
   jq \
-  bc \
+  ca-certificates \
+  && apt-get clean \
+  && rm -rf /var/lib/apt/lists/*
+
+# --- STAGE 2: Maintainer (Parent of Sandbox) ---
+FROM base AS maintainer
+
+# Install "Maintainer Bloat" - tools needed for development and offloading
+RUN apt-get update && apt-get install -y --no-install-recommends \
+  make \
+  g++ \
   gh \
   git \
   unzip \
@@ -25,21 +30,31 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   psmisc \
   lsof \
   socat \
-  ca-certificates \
+  build-essential \
+  libsecret-1-dev \
+  libkrb5-dev \
   && apt-get clean \
   && rm -rf /var/lib/apt/lists/*
 
-# set up npm global package folder under /usr/local/share
-# give it to non-root user node, already set up in base image
+# Install global dev tools
+RUN npm install -g tsx vitest
+
+# Set up npm global package folder
 RUN mkdir -p /usr/local/share/npm-global \
   && chown -R node:node /usr/local/share/npm-global
 ENV NPM_CONFIG_PREFIX=/usr/local/share/npm-global
 ENV PATH=$PATH:/usr/local/share/npm-global/bin
 
-# switch to non-root user node
+# --- STAGE 3: Sandbox (Final CLI Image) ---
+FROM maintainer AS sandbox
+
+ARG SANDBOX_NAME="gemini-cli-sandbox"
+ENV SANDBOX="$SANDBOX_NAME"
+
+# Switch to non-root user node
 USER node
 
-# install gemini-cli and clean up
+# Install gemini-cli and clean up
 COPY packages/cli/dist/google-gemini-cli-*.tgz /tmp/gemini-cli.tgz
 COPY packages/core/dist/google-gemini-cli-core-*.tgz /tmp/gemini-core.tgz
 RUN npm install -g /tmp/gemini-core.tgz \
@@ -49,5 +64,5 @@ RUN npm install -g /tmp/gemini-core.tgz \
   && npm cache clean --force \
   && rm -f /tmp/gemini-{cli,core}.tgz
 
-# default entrypoint when none specified
+# Default entrypoint
 CMD ["gemini"]