chore: import upstream snapshot with attribution

cli-tool/components/sandbox/docker/Dockerfile

@@ -0,0 +1,38 @@
+# syntax=docker/dockerfile:1
+FROM node:22-alpine
+
+# Install runtime dependencies
+RUN apk --no-cache add \
+    git \
+    bash \
+    python3 \
+    py3-pip \
+    curl \
+    && npm install -g @anthropic-ai/claude-agent-sdk
+
+# Create non-root user for security
+RUN adduser -u 10001 -D -s /bin/bash sandboxuser
+
+# Set working directory
+WORKDIR /app
+
+# Create output directory
+RUN mkdir -p /output && chown sandboxuser:sandboxuser /output
+
+# Copy execution script
+COPY execute.js /app/execute.js
+COPY package.json /app/package.json
+
+# Install dependencies
+RUN npm install --production && \
+    chown -R sandboxuser:sandboxuser /app
+
+# Switch to non-root user
+USER sandboxuser
+
+# Set environment
+ENV HOME=/home/sandboxuser
+ENV NODE_ENV=production
+
+# Default command (overridden by launcher)
+CMD ["node", "/app/execute.js"]