fix(acceptance): 对齐负载报告第二版契约

生产验收统一校验并合并 acceptance-load-report/v2，避免成功负载因旧版 schemaVersion 断言被误判失败。\n\n已执行 bash -n、ShellCheck 和 production acceptance 脚本测试。

tests/release/production-acceptance-script-test.sh

@@ -7,6 +7,11 @@ tmp=$(mktemp -d)
 trap 'rm -rf "$tmp"' EXIT
 
 script=$root/scripts/cluster/run-production-acceptance.sh
+grep -Fq 'acceptance-load-report/v2' "$script"
+if grep -Fq 'acceptance-load-report/v1' "$script"; then
+  echo 'production acceptance still requires the obsolete load report v1 schema' >&2
+  exit 1
+fi
 
 # shellcheck source=scripts/cluster/common.sh
 source "$root/scripts/cluster/common.sh"