fix(acceptance): 按隔离额度执行平台降级路由

让 acceptance 候选负载读取同一 Run ID 下的并发、RPM 和 TPM 计数器，并在单个平台模型额度不足时继续尝试下一候选，生产与 canary 额度作用域保持不变。\n\n补齐本地容量控制器对宁波和香港测试 Worker 的最小 RBAC，避免初次应用生产反亲和配置时发生滚动死锁，并将突发负载对齐到完整限流窗口。\n\n验证：\n- go test ./internal/runner ./internal/store -count=1\n- go vet ./internal/runner ./internal/store\n- bash -n scripts/acceptance/local-cluster.sh scripts/acceptance/provider-burst.sh scripts/acceptance/run-local-acceptance.sh\n- shellcheck -x scripts/acceptance/local-cluster.sh scripts/acceptance/provider-burst.sh scripts/acceptance/run-local-acceptance.sh\n- kubectl apply --dry-run=client -f deploy/kubernetes/local-acceptance/capacity-controller-rbac.yaml

apps/api/internal/runner/admission.go

@@ -103,6 +103,7 @@ func (s *Service) buildTaskAdmissionPlanForCurrentBinding(
 		CacheAffinityKey:    cacheAffinityKeys.Primary,
 		CacheAffinityKeys:   cacheAffinityKeys.Lookup,
 		CacheAffinityPolicy: runnerPolicy.CacheAffinityPolicy,
+		QuotaScopePrefix:    acceptanceQuotaScopePrefix(task),
 	})
 	if err == nil {
 		candidates, err = filterCandidatesByRequestedPlatform(candidates, body)
@@ -120,6 +121,7 @@ func (s *Service) buildTaskAdmissionPlanForCurrentBinding(
 		return taskAdmissionPlan{}, err
 	}
 	candidates, _ = pinCandidatesToTaskAdmission(candidates, admission)
+	var candidateRateLimitErr error
 	for _, candidate := range candidates {
 		available, availabilityErr := s.store.RuntimeCandidateAvailable(ctx, candidate.PlatformID, candidate.PlatformModelID)
 		if availabilityErr != nil {
@@ -151,6 +153,13 @@ func (s *Service) buildTaskAdmissionPlanForCurrentBinding(
 			s.rateLimitReservations(ctx, user, candidate, body),
 		)
 		if err := s.store.CheckRateLimits(ctx, reservations); err != nil {
+			var limitErr *store.RateLimitExceededError
+			if errors.As(err, &limitErr) && limitErr.ScopeType == "platform_model" {
+				if candidateRateLimitErr == nil {
+					candidateRateLimitErr = err
+				}
+				continue
+			}
 			return taskAdmissionPlan{}, err
 		}
 		return taskAdmissionPlan{
@@ -162,6 +171,9 @@ func (s *Service) buildTaskAdmissionPlanForCurrentBinding(
 			Eligible:  true,
 		}, nil
 	}
+	if candidateRateLimitErr != nil {
+		return taskAdmissionPlan{}, candidateRateLimitErr
+	}
 	return taskAdmissionPlan{}, store.ErrNoModelCandidate
 }
 
@@ -239,6 +251,13 @@ func acceptanceScopeKey(task store.GatewayTask, scopeKey string) string {
 	return "acceptance:" + runID + ":" + scopeKey
 }
 
+func acceptanceQuotaScopePrefix(task store.GatewayTask) string {
+	if task.RunMode != "acceptance" {
+		return ""
+	}
+	return acceptanceScopeKey(task, "")
+}
+
 func (s *Service) loadAsyncTaskAdmission(ctx context.Context, task store.GatewayTask) (*store.TaskAdmission, error) {
 	if !task.AsyncMode {
 		return nil, nil