fix(worker): 拆分准入事务并收敛验收失败状态

将批量准入改为每任务独立事务，避免 P24 压测时 48 条任务共享长事务造成 transactionid 锁潮与 Worker 槽位空转。失败验收在保持 validation 的同时清理未提交任务，并记录精确压力门禁原因。统一生产 0+2 Worker 拓扑、运行时 ConfigMap 与发布配置，补充镜像预检诊断和回归测试。\n\n验证：Go 全量测试、go vet、真实 PostgreSQL 48 任务集成测试、迁移安全检查、发布脚本测试、bash -n、ShellCheck、Compose 配置均通过。

deploy/kubernetes/easyai-ai-gateway-cluster-release.conf.example

@@ -6,8 +6,8 @@ DESIRED_STATE_DIR=/usr/local/share/easyai-ai-gateway-release/production
 
 # Worker 容量只需修改本发布配置并执行获授权的 `capacity`，不再修改 Go 代码。
 # 副本数属于 Deployment 配置，不能由容器内部环境变量改变；发布工具读取这两个变量并写入 replicas。
-AI_GATEWAY_WORKER_REPLICAS_NINGBO=1
-AI_GATEWAY_WORKER_REPLICAS_HONGKONG=1
+AI_GATEWAY_WORKER_REPLICAS_NINGBO=0
+AI_GATEWAY_WORKER_REPLICAS_HONGKONG=2
 AI_GATEWAY_ASYNC_WORKER_INSTANCE_HARD_LIMIT=24
 AI_GATEWAY_ASYNC_WORKER_HARD_LIMIT=48
 AI_GATEWAY_ASYNC_WORKER_GLOBAL_HARD_LIMIT=48
@@ -23,10 +23,10 @@ AI_GATEWAY_DATABASE_MAX_CONN_IDLE_SECONDS=30
 AI_GATEWAY_MEDIA_MATERIALIZATION_CONCURRENCY=24
 AI_GATEWAY_MEDIA_REQUEST_CONCURRENCY=24
 AI_GATEWAY_WORKER_AUTOSCALING_ENABLED=false
-AI_GATEWAY_WORKER_MIN_REPLICAS_NINGBO=1
+AI_GATEWAY_WORKER_MIN_REPLICAS_NINGBO=0
 AI_GATEWAY_WORKER_MIN_REPLICAS_HONGKONG=1
-AI_GATEWAY_WORKER_MAX_REPLICAS_NINGBO=1
-AI_GATEWAY_WORKER_MAX_REPLICAS_HONGKONG=1
+AI_GATEWAY_WORKER_MAX_REPLICAS_NINGBO=0
+AI_GATEWAY_WORKER_MAX_REPLICAS_HONGKONG=2
 AI_GATEWAY_WORKER_TARGET_OUTSTANDING_PER_REPLICA=48
 AI_GATEWAY_WORKER_SCALE_UP_WINDOW_SECONDS=20
 AI_GATEWAY_WORKER_SCALE_DOWN_STABILIZATION_SECONDS=600