perf(cd): skip redundant mirror and bootstrap work

scripts/ci/bootstrap-host-runner-tools.sh

@@ -0,0 +1,43 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+required_commands=(node npm git curl bash timeout python3 ssh docker)
+missing_commands=()
+
+for command_name in "${required_commands[@]}"; do
+  if ! command -v "${command_name}" >/dev/null 2>&1; then
+    missing_commands+=("${command_name}")
+  fi
+done
+
+if command -v docker >/dev/null 2>&1 && \
+   ! docker buildx version >/dev/null 2>&1; then
+  missing_commands+=(docker-buildx)
+fi
+
+if [ "${#missing_commands[@]}" -eq 0 ]; then
+  echo "host_runner_tools_ready=1 bootstrap_install_performed=0"
+  exit 0
+fi
+
+printf 'host_runner_tools_missing=%s\n' "$(IFS=,; echo "${missing_commands[*]}")"
+if ! command -v apk >/dev/null 2>&1; then
+  echo "BLOCKER host_runner_tools_missing_and_apk_unavailable"
+  exit 1
+fi
+
+apk add --no-cache \
+  nodejs npm git curl bash coreutils python3 openssh-client docker-cli docker-cli-buildx
+
+for command_name in "${required_commands[@]}"; do
+  command -v "${command_name}" >/dev/null 2>&1 || {
+    echo "BLOCKER host_runner_tool_install_failed command=${command_name}"
+    exit 1
+  }
+done
+docker buildx version >/dev/null 2>&1 || {
+  echo "BLOCKER host_runner_tool_install_failed command=docker-buildx"
+  exit 1
+}
+
+echo "host_runner_tools_ready=1 bootstrap_install_performed=1"