fix(acceptance): 联动压力采样与负载停止

零副本 Worker 站点没有 metrics，应从聚合采样中跳过；有副本的站点采样失败仍保持硬失败。补充缺失字段诊断，避免只输出无上下文的采样失败。\n\n容量轮次和混合长稳压测现在持续监视压力采样进程；采样器提前退出时立即终止当前负载并走失败收口，避免在资源监控失效后继续造任务。\n\n验证：bash -n、ShellCheck、零副本站点测试、采样失败联动停止测试、manual-release-test。

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

@@ -1,4 +1,5 @@
 #!/usr/bin/env bash
+# shellcheck disable=SC2034 # Variables are consumed by dynamically sourced functions.
 set -euo pipefail
 
 root=$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)
@@ -15,6 +16,15 @@ awk '
 # shellcheck source=/dev/null
 source "$tmp/is-release-ancestor.sh"
 
+awk '
+  /^workload_metrics_for_site\(\)/ { capture = 1 }
+  capture && /^current_max_pod_memory_mib\(\)/ { exit }
+  capture { print }
+' "$script" >"$tmp/pressure-monitor.sh"
+
+# shellcheck source=/dev/null
+source "$tmp/pressure-monitor.sh"
+
 cluster_root=$tmp/repository
 git init -q "$cluster_root"
 git -C "$cluster_root" config user.name 'Acceptance Script Test'
@@ -35,4 +45,39 @@ if is_release_ancestor invalid "$third"; then
   exit 1
 fi
 
+remote_kubectl() {
+  printf 0
+}
+
+cluster_ssh() {
+  echo 'zero-replica Worker attempted to collect metrics' >&2
+  return 1
+}
+
+namespace=easyai
+if workload_metrics_for_site worker ningbo; then
+  echo 'zero-replica Worker site returned metrics success' >&2
+  exit 1
+else
+  metrics_status=$?
+fi
+[[ $metrics_status == 2 ]]
+
+long_running_load() {
+  while :; do
+    sleep 1
+  done
+}
+
+(sleep 1; exit 1) &
+pressure_pid=$!
+AI_GATEWAY_ACCEPTANCE_PROCESS_WATCH_SECONDS=1
+active_load_pid=
+if run_with_pressure_monitor "$pressure_pid" long_running_load; then
+  echo 'load continued after the pressure sampler failed' >&2
+  exit 1
+fi
+wait "$pressure_pid" >/dev/null 2>&1 || true
+[[ -z $active_load_pid ]]
+
 echo 'production_acceptance_script_tests=PASS'