chore: strip monorepo; keep Docker runtime deploy for official dsh@latest

Image installs @deepseek-ai/dsh from npm on start. Fork 0.1.2-alpha.2 source
is obsolete for this deployment path.

docker/ensure-rust.sh

@@ -0,0 +1,40 @@
+#!/bin/sh
+# Rust 按需安装包装器：镜像里 /usr/local/bin/{cargo,rustc,rustup} 都是指向本脚本的软链接。
+# 首次调用任一命令时，用 rustup-init 把最小 stable toolchain 装进 dsh-data 持久卷
+# （RUSTUP_HOME/CARGO_HOME 已在镜像 ENV 中指向 /home/dsh/.dsh/...），之后直接转发到真实二进制。
+# toolchain 通过 RUSTUP_DIST_SERVER（USTC 镜像）下载，重启容器后已装的 toolchain 仍保留。
+set -eu
+
+: "${RUSTUP_HOME:=/home/dsh/.dsh/rustup}"
+: "${CARGO_HOME:=/home/dsh/.dsh/cargo}"
+export RUSTUP_HOME CARGO_HOME
+
+cmd="$(basename "$0")"
+target="${CARGO_HOME}/bin/${cmd}"
+
+if [ ! -x "$target" ]; then
+  lockdir="${RUSTUP_HOME}/.installing"
+  mine=0
+  # 并发首次调用只允许一个进程执行 rustup-init，其余进程等待它完成。
+  while [ "$mine" -eq 0 ]; do
+    if mkdir "$lockdir" 2>/dev/null; then
+      mine=1
+    elif [ -x "$target" ]; then
+      break
+    else
+      sleep 2
+    fi
+  done
+  if [ ! -x "$target" ]; then
+    rustup-init -y --profile minimal --default-toolchain stable --no-modify-path >&2
+  fi
+  if [ "$mine" -eq 1 ]; then
+    rmdir "$lockdir" 2>/dev/null || true
+  fi
+  if [ ! -x "$target" ]; then
+    echo "ensure-rust: rustup-init failed to install ${cmd}; check network and retry." >&2
+    exit 1
+  fi
+fi
+
+exec "$target" "$@"