feat(queue): 增加非文本模型分布式准入队列

使用 PostgreSQL 统一同步与异步非文本任务的并发准入、持久化等待和 Worker 容量分配，并将生产 API 与独立 Worker 角色拆分。

补充策略管理、共享契约、OpenAPI、Kubernetes 双节点 Worker 清单及跨节点验收脚本；未默认启用任何生产 queue_size 策略。

已在原基线完成 Go、前端、迁移、Shell、Kustomize 与长任务容量验收；合入最新主干后将重新执行发布门禁。

scripts/cluster/migrate-production.sh

@@ -114,7 +114,9 @@ rollback_before_commit() {
   if [[ $traffic_committed == false ]]; then
     echo '[cutover] rolling back to the frozen Docker database' >&2
     k3s kubectl scale deployment -n easyai \
-      easyai-api-ningbo easyai-api-hongkong easyai-web-ningbo easyai-web-hongkong \
+      easyai-api-ningbo easyai-api-hongkong \
+      easyai-worker-ningbo easyai-worker-hongkong \
+      easyai-web-ningbo easyai-web-hongkong \
       --replicas=0 >/dev/null 2>&1 || true
     docker start easyai-ai-gateway-api-1 easyai-ai-gateway-web-1 >/dev/null 2>&1 || true
     if [[ -f $old_site_backup ]]; then
@@ -312,7 +314,9 @@ set -euo pipefail
 backup_directory=$(cat /root/.easyai-pre-cutover-backup)
 [[ $backup_directory == /var/backups/easyai-ai-gateway/pre-cutover-* ]]
 k3s kubectl scale deployment -n easyai \
-  easyai-api-ningbo easyai-api-hongkong easyai-web-ningbo easyai-web-hongkong \
+  easyai-api-ningbo easyai-api-hongkong \
+  easyai-worker-ningbo easyai-worker-hongkong \
+  easyai-web-ningbo easyai-web-hongkong \
   --replicas=0 >/dev/null 2>&1 || true
 docker start easyai-ai-gateway-api-1 easyai-ai-gateway-web-1 >/dev/null
 install -m 0644 "$backup_directory/nginx-site.conf" \
@@ -325,7 +329,7 @@ REMOTE
 }
 trap rollback_local_before_commit ERR
 
-echo '[cutover] starting both application sites with River workers frozen'
+echo '[cutover] starting both application sites with dedicated workers frozen'
 AI_GATEWAY_ACTIVATE_WORKERS=false \
   "$script_dir/bootstrap-platform.sh" activate "$release_manifest"
 
@@ -352,12 +356,10 @@ echo '[cutover] traffic committed; enabling Hong Kong worker, then Ningbo worker
 cluster_ssh "$CLUSTER_NINGBO_HOST" 'bash -s' <<'REMOTE'
 set -euo pipefail
 kubectl='k3s kubectl'
-$kubectl set env deployment/easyai-api-hongkong -n easyai \
-  AI_GATEWAY_ASYNC_QUEUE_WORKER_ENABLED=true
-$kubectl rollout status deployment/easyai-api-hongkong -n easyai --timeout=300s
-$kubectl set env deployment/easyai-api-ningbo -n easyai \
-  AI_GATEWAY_ASYNC_QUEUE_WORKER_ENABLED=true
-$kubectl rollout status deployment/easyai-api-ningbo -n easyai --timeout=300s
+$kubectl scale deployment/easyai-worker-hongkong -n easyai --replicas=1
+$kubectl rollout status deployment/easyai-worker-hongkong -n easyai --timeout=300s
+$kubectl scale deployment/easyai-worker-ningbo -n easyai --replicas=1
+$kubectl rollout status deployment/easyai-worker-ningbo -n easyai --timeout=300s
 backup_resource=$(cat <<'EOF' | $kubectl create -f - -o name
 apiVersion: postgresql.cnpg.io/v1
 kind: Backup