perf(worker): 批量填充异步执行槽

跨地域同步复制下逐任务准入会为每个 River Job 支付一次事务提交 RTT，导致 P24 实际只能维持少量运行任务。调度器现在按全局容量窗口准备 FIFO 批次，在同一 PostgreSQL 事务内逐项校验队首、创建租约并插入唯一 River Job，一次提交即可填满可用槽；任一 Hook 失败时整批原子回滚。\n\n验收压力采样同时排除正在终止的 Ready Pod，避免滚动切换期间误连已移除容器。\n\n验证：真实 PostgreSQL 批量提交及整批回滚集成测试、Go 全量测试、go vet、runner/store race、gofmt、bash -n、ShellCheck、迁移安全检查通过。

apps/api/internal/runner/admission.go

@@ -3,6 +3,7 @@ package runner
 import (
 	"context"
 	"errors"
+	"fmt"
 	"hash/fnv"
 	"strings"
 	"time"
@@ -279,25 +280,42 @@ func (s *Service) tryTaskAdmissionWithAdmittedHook(
 	waiterID string,
 	onAdmitted func(pgx.Tx) error,
 ) (store.TaskAdmissionResult, error) {
-	input := taskAdmissionInput(task, plan, waiterID)
-	current, currentErr := s.store.GetTaskAdmission(ctx, task.ID)
-	if currentErr != nil && !errors.Is(currentErr, pgx.ErrNoRows) {
-		return store.TaskAdmissionResult{}, currentErr
-	}
-	if currentErr == nil && current.Status == "waiting" &&
-		(current.PlatformID != input.PlatformID || current.PlatformModelID != input.PlatformModelID || current.UserGroupID != input.UserGroupID) {
-		if _, rebindErr := s.store.RebindWaitingTaskAdmission(ctx, input); rebindErr != nil {
-			return store.TaskAdmissionResult{}, rebindErr
-		}
-		s.observeTaskAdmission("candidate_migrated")
+	input, err := s.prepareTaskAdmissionInput(ctx, task, plan, waiterID)
+	if err != nil {
+		return store.TaskAdmissionResult{}, err
 	}
 	var result store.TaskAdmissionResult
-	var err error
 	if onAdmitted == nil {
 		result, err = s.store.TryTaskAdmission(ctx, input)
 	} else {
 		result, err = s.store.TryTaskAdmissionWithAdmittedHook(ctx, input, onAdmitted)
 	}
+	s.observeTaskAdmissionAttempt(result, err)
+	return result, err
+}
+
+func (s *Service) prepareTaskAdmissionInput(
+	ctx context.Context,
+	task store.GatewayTask,
+	plan taskAdmissionPlan,
+	waiterID string,
+) (store.TaskAdmissionInput, error) {
+	input := taskAdmissionInput(task, plan, waiterID)
+	current, currentErr := s.store.GetTaskAdmission(ctx, task.ID)
+	if currentErr != nil && !errors.Is(currentErr, pgx.ErrNoRows) {
+		return store.TaskAdmissionInput{}, currentErr
+	}
+	if currentErr == nil && current.Status == "waiting" &&
+		(current.PlatformID != input.PlatformID || current.PlatformModelID != input.PlatformModelID || current.UserGroupID != input.UserGroupID) {
+		if _, rebindErr := s.store.RebindWaitingTaskAdmission(ctx, input); rebindErr != nil {
+			return store.TaskAdmissionInput{}, rebindErr
+		}
+		s.observeTaskAdmission("candidate_migrated")
+	}
+	return input, nil
+}
+
+func (s *Service) observeTaskAdmissionAttempt(result store.TaskAdmissionResult, err error) {
 	if result.NewlyAdmitted {
 		s.observeTaskAdmission("admitted")
 		s.observeTaskAdmissionWait(time.Since(result.Admission.EnqueuedAt))
@@ -309,7 +327,6 @@ func (s *Service) tryTaskAdmissionWithAdmittedHook(
 	case errors.Is(err, store.ErrQueueTimeout):
 		s.observeTaskAdmission("timeout")
 	}
-	return result, err
 }
 
 func taskAdmissionInput(task store.GatewayTask, plan taskAdmissionPlan, waiterID string) store.TaskAdmissionInput {
@@ -603,25 +620,61 @@ func (s *Service) SubmitAsyncTask(ctx context.Context, task store.GatewayTask) e
 	return nil
 }
 
-func (s *Service) dispatchWaitingAsyncTask(ctx context.Context, task store.GatewayTask) (bool, error) {
-	user := authUserFromTask(task)
-	plan, err := s.buildTaskAdmissionPlan(ctx, task, user)
-	if err != nil {
-		return false, err
+func (s *Service) dispatchWaitingAsyncTasks(ctx context.Context, tasks []store.GatewayTask) (bool, error) {
+	if len(tasks) == 0 {
+		return false, nil
 	}
-	if !plan.Eligible {
-		if err := s.EnqueueAsyncTask(ctx, task); err != nil {
+	inputs := make([]store.TaskAdmissionInput, 0, len(tasks))
+	tasksByID := make(map[string]store.GatewayTask, len(tasks))
+	for _, task := range tasks {
+		user := authUserFromTask(task)
+		plan, err := s.buildTaskAdmissionPlan(ctx, task, user)
+		if err != nil {
 			return false, err
 		}
-		return true, nil
+		if !plan.Eligible {
+			if err := s.EnqueueAsyncTask(ctx, task); err != nil {
+				return false, err
+			}
+			continue
+		}
+		input, err := s.prepareTaskAdmissionInput(ctx, task, plan, "")
+		if err != nil {
+			return false, err
+		}
+		inputs = append(inputs, input)
+		tasksByID[task.ID] = task
 	}
-	result, err := s.tryTaskAdmissionWithAdmittedHook(ctx, task, plan, "", func(tx pgx.Tx) error {
-		return s.enqueueAsyncTaskTx(ctx, tx, task.ID, asyncTaskInsertOpts(task))
-	})
+	outcomes, err := s.store.TryTaskAdmissionBatchWithAdmittedHook(
+		ctx,
+		inputs,
+		func(tx pgx.Tx, input store.TaskAdmissionInput) error {
+			task, ok := tasksByID[input.TaskID]
+			if !ok {
+				return fmt.Errorf("async admission batch task %s was not prepared", input.TaskID)
+			}
+			return s.enqueueAsyncTaskTx(ctx, tx, task.ID, asyncTaskInsertOpts(task))
+		},
+	)
 	if err != nil {
 		return false, err
 	}
-	return result.Admitted, nil
+	saturated := false
+	for _, outcome := range outcomes {
+		s.observeTaskAdmissionAttempt(outcome.Result, outcome.Err)
+		if outcome.Err != nil {
+			if errors.Is(outcome.Err, store.ErrTaskExecutionFinished) ||
+				errors.Is(outcome.Err, store.ErrQueueTimeout) {
+				continue
+			}
+			return false, outcome.Err
+		}
+		if !outcome.Result.Admitted {
+			saturated = true
+			break
+		}
+	}
+	return saturated, nil
 }
 
 func (s *Service) cancelAsyncSubmissionIfDisconnected(ctx context.Context, taskID string) bool {
@@ -650,11 +703,19 @@ func (s *Service) dispatchWaitingAsyncAdmissions(ctx context.Context) {
 		case <-s.asyncAdmissionWake:
 		case <-ticker.C:
 		}
-		taskIDs, err := s.store.ListWaitingAsyncAdmissionTaskIDs(ctx, 1000)
+		batchLimit := s.cfg.AsyncWorkerHardLimit
+		if batchLimit <= 0 {
+			batchLimit = 64
+		}
+		if batchLimit > 128 {
+			batchLimit = 128
+		}
+		taskIDs, err := s.store.ListWaitingAsyncAdmissionTaskIDs(ctx, batchLimit)
 		if err != nil {
 			s.logger.Warn("list waiting async admissions failed", "error", err)
 			continue
 		}
+		tasks := make([]store.GatewayTask, 0, len(taskIDs))
 		for _, taskID := range taskIDs {
 			task, err := s.store.GetTask(ctx, taskID)
 			if err != nil {
@@ -666,18 +727,18 @@ func (s *Service) dispatchWaitingAsyncAdmissions(ctx context.Context) {
 			if task.Status != "queued" {
 				continue
 			}
-			admitted, err := s.dispatchWaitingAsyncTask(ctx, task)
-			if err != nil {
-				s.logger.Warn("dispatch waiting async admission failed", "taskID", taskID, "error", err)
-				continue
-			}
-			if !admitted {
-				// Every asynchronous task shares the global worker-capacity FIFO
-				// scope. Once its current head cannot be admitted, later tasks
-				// cannot make progress until a lease is released.
-				s.observeTaskAdmission("dispatch_saturated")
-				break
-			}
+			tasks = append(tasks, task)
+		}
+		saturated, err := s.dispatchWaitingAsyncTasks(ctx, tasks)
+		if err != nil {
+			s.logger.Warn("dispatch waiting async admission batch failed", "tasks", len(tasks), "error", err)
+			continue
+		}
+		if saturated {
+			// Every asynchronous task shares the global worker-capacity FIFO
+			// scope. Once its current head cannot be admitted, later tasks
+			// cannot make progress until a lease is released.
+			s.observeTaskAdmission("dispatch_saturated")
 		}
 	}
 }