ci: centralize docker build wrapper

scripts/docker/setup.sh

@@ -2,6 +2,7 @@
 set -euo pipefail
 
 ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+source "$ROOT_DIR/scripts/lib/docker-build.sh"
 COMPOSE_FILE="$ROOT_DIR/docker-compose.yml"
 EXTRA_COMPOSE_FILE="$ROOT_DIR/docker-compose.extra.yml"
 IMAGE_NAME="${OPENCLAW_IMAGE:-openclaw:local}"
@@ -27,7 +28,7 @@ require_cmd() {
 run_docker_build() {
   # Dockerfile uses BuildKit-only syntax (RUN --mount=type=cache). Force
   # BuildKit so hosts defaulting to the legacy builder do not fail.
-  DOCKER_BUILDKIT=1 docker build "$@"
+  docker_build_exec "$@"
 }
 
 is_truthy_value() {