fix(deploy): 适配宁波 NGINX 配置加载路径

宁波 NGINX 仅加载 conf.d/*.conf，原切换脚本写入 sites-enabled 后不会生效。统一将维护页、集群入口和回滚配置写入实际加载的 conf.d 入口，并保留切换前配置备份。\n\n验证：bash -n、ShellCheck、git diff --check、双节点 nginx -t 与 prepare。

scripts/cluster/migrate-production.sh

@@ -101,7 +101,7 @@ set -euo pipefail
 
 source_sha=$1
 api_image=$2
-active_site=${AI_GATEWAY_NGINX_ACTIVE_SITE:-/etc/nginx/sites-enabled/ai.51easyai.com}
+active_site=${AI_GATEWAY_NGINX_ACTIVE_SITE:-/etc/nginx/conf.d/easyai-ai-gateway-ai.51easyai.com.conf}
 timestamp=$(date -u '+%Y%m%dT%H%M%SZ')
 backup_directory=/var/backups/easyai-ai-gateway/pre-cutover-"$timestamp"
 old_site_backup=$backup_directory/nginx-site.conf
@@ -118,9 +118,7 @@ rollback_before_commit() {
       --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 $old_site_backup ]]; then
-      install -m 0644 "$old_site_backup" /etc/nginx/sites-available/ai.51easyai.com-pre-ha
-      rm -f -- "$active_site"
-      ln -s /etc/nginx/sites-available/ai.51easyai.com-pre-ha "$active_site"
+      install -m 0644 "$old_site_backup" "$active_site"
       nginx -t && systemctl reload nginx
     fi
   else
@@ -137,8 +135,7 @@ install -d -m 0700 "$backup_directory"
 }
 cp -L "$active_site" "$old_site_backup"
 chmod 0600 "$old_site_backup"
-rm -f -- "$active_site"
-ln -s /etc/nginx/sites-available/ai.51easyai.com-maintenance "$active_site"
+install -m 0644 /etc/nginx/sites-available/ai.51easyai.com-maintenance "$active_site"
 nginx -t
 systemctl reload nginx
 curl -ksS --resolve ai.51easyai.com:443:127.0.0.1 \
@@ -310,11 +307,8 @@ k3s kubectl scale deployment -n easyai \
   easyai-api-ningbo easyai-api-hongkong easyai-web-ningbo easyai-web-hongkong \
   --replicas=0 >/dev/null 2>&1 || true
 docker start easyai-ai-gateway-api-1 easyai-ai-gateway-web-1 >/dev/null
-rm -f -- /etc/nginx/sites-enabled/ai.51easyai.com
 install -m 0644 "$backup_directory/nginx-site.conf" \
-  /etc/nginx/sites-available/ai.51easyai.com-pre-ha
-ln -s /etc/nginx/sites-available/ai.51easyai.com-pre-ha \
-  /etc/nginx/sites-enabled/ai.51easyai.com
+  /etc/nginx/conf.d/easyai-ai-gateway-ai.51easyai.com.conf
 nginx -t
 systemctl reload nginx
 REMOTE