Route cluster metadata to writable primary

scripts/test-metadata.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+set -eu
+cd "$(dirname "$0")/.."
+project="objectstore-metadata-test-$$"
+compose() { docker compose -p "$project" -f tests/metadata/compose.yaml "$@"; }
+trap 'compose down -v --remove-orphans >/dev/null 2>&1 || true' EXIT
+compose up --build --abort-on-container-exit --exit-code-from check check