chore: import upstream snapshot with attribution

Dockerfile

@@ -0,0 +1,70 @@
+FROM node:22-alpine AS node
+
+WORKDIR /app
+
+COPY web ./web
+
+RUN cd web && npm install && npx vite build
+
+# Build nsjail from source so the image ships a self-contained sandbox backend
+# that needs no host Docker socket. Pinned to a release tag for reproducibility.
+# Multi-stage keeps the compile toolchain (bison/flex/protobuf-dev/libnl-dev)
+# out of the final image; only the nsjail binary and its small runtime libs
+# (libprotobuf, libnl-route-3) are carried over.
+FROM python:3.12.7-slim AS nsjail-build
+
+ARG NSJAIL_VERSION=3.6
+
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends \
+        ca-certificates git build-essential \
+        autoconf bison flex libtool pkg-config \
+        protobuf-compiler libprotobuf-dev libnl-route-3-dev \
+    && git clone --depth 1 --branch "${NSJAIL_VERSION}" https://github.com/google/nsjail.git /nsjail \
+    && make -C /nsjail \
+    && install -m 0755 /nsjail/nsjail /usr/local/bin/nsjail \
+    && rm -rf /var/lib/apt/lists/*
+
+FROM python:3.12.7-slim
+
+WORKDIR /app
+
+COPY . .
+
+COPY --from=node /app/web/dist ./web/dist
+
+# nsjail binary built in the dedicated stage above. Self-contained sandbox
+# backend; lets the Box runtime isolate code without a host Docker socket.
+COPY --from=nsjail-build /usr/local/bin/nsjail /usr/local/bin/nsjail
+
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends gcc ca-certificates curl gnupg \
+    # nsjail runtime libraries (the build toolchain stays in the nsjail-build
+    # stage; only these shared libs are needed to execute the binary).
+    && apt-get install -y --no-install-recommends libprotobuf32 libnl-route-3-200 \
+    # Install the Docker CLI (client only) so the optional langbot_box
+    # service can drive the mounted host Docker socket and create sandbox
+    # containers. The same image powers langbot / plugin_runtime / box; only
+    # box uses the client. Arch-aware via dpkg so multi-arch builds work.
+    && install -m 0755 -d /etc/apt/keyrings \
+    && curl -fsSL https://download.docker.com/linux/debian/gpg -o /etc/apt/keyrings/docker.asc \
+    && chmod a+r /etc/apt/keyrings/docker.asc \
+    && echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/debian $(. /etc/os-release && echo \"$VERSION_CODENAME\") stable" > /etc/apt/sources.list.d/docker.list \
+    && apt-get update \
+    && apt-get install -y --no-install-recommends docker-ce-cli \
+    # Install Node.js LTS so the sandbox (nsjail/Docker box) can run npx-based
+    # stdio MCP servers. node/npx land in /usr/bin, which is on the nsjail
+    # read-only mount whitelist (_READONLY_SYSTEM_MOUNTS), so they are bound
+    # into the sandbox chroot automatically. Without node, any npx-launched
+    # MCP server exits with return_code=127 (command not found).
+    && curl -fsSL https://deb.nodesource.com/setup_22.x -o /tmp/nodesource_setup.sh \
+    && bash /tmp/nodesource_setup.sh \
+    && apt-get install -y --no-install-recommends nodejs \
+    && rm -f /tmp/nodesource_setup.sh \
+    && python -m pip install --no-cache-dir uv \
+    && uv sync \
+    && apt-get purge -y --auto-remove curl gnupg \
+    && rm -rf /var/lib/apt/lists/* \
+    && touch /.dockerenv
+
+CMD [ "uv", "run", "--no-sync", "main.py" ]