fix(acceptance): 避免用户组阻塞候选队列

验收用户组仅承担身份和账务隔离，不再创建非约束性的组级并发队列，避免不同生产候选之间出现 FIFO 队头阻塞。真实候选自身的并发、排队和限流策略保持不变。\n\n验证：bash -n；ShellCheck；git diff --check。

scripts/cluster/run-production-acceptance.sh

@@ -238,13 +238,7 @@ ensure_acceptance_user_group() {
     priority:1,
     rechargeDiscountPolicy:{},
     billingDiscountPolicy:{},
-    rateLimitPolicy:{
+    rateLimitPolicy:{rules:[]},
-      rules:[{
-        metric:"concurrent",
-        limit:1000,
-        leaseTtlSeconds:600
-      }]
-    },
     quotaPolicy:{},
     metadata:{purpose:"production_acceptance",isolated:true},
     status:"active"
@@ -342,7 +336,13 @@ SELECT
    FROM gateway_user_groups
    WHERE id='$group_id'::uuid
      AND status='active'
-     AND rate_limit_policy @> '{\"rules\":[{\"metric\":\"concurrent\",\"limit\":1000}]}'::jsonb)
+     AND NOT EXISTS (
+       SELECT 1
+       FROM jsonb_array_elements(
+         COALESCE(rate_limit_policy->'rules','[]'::jsonb)
+       ) rule
+       WHERE rule->>'metric' IN ('concurrent','queue_size')
+     ))
   ||':'||
   (SELECT count(*)
    FROM gateway_users
@@ -357,7 +357,7 @@ SELECT
     echo 'dedicated acceptance identity isolation verification failed' >&2
     return 1
   }
-  echo 'acceptance_user_group=PASS concurrent_limit=1000 active_keys=1 isolated=true'
+  echo 'acceptance_user_group=PASS rate_limit=production_candidates active_keys=1 isolated=true'
 }
 
 select_acceptance_models() {