fix(ci): 修复部署流水线配置

- 使用 Git commit hash 作为镜像标签
- 增加健康检查超时到 15 秒
- 添加镜像清理阶段（保留 7 天）

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Jenkinsfile

@@ -1,7 +1,7 @@
 pipeline {
     agent none
     environment {
-        IMAGE_NAME = 'lpt-fe:0.0'
+        IMAGE_NAME = "lpt-fe:${env.GIT_COMMIT?.take(8) ?: '0.0'}"
         CONTAINER_NAME = 'LPT_FE'
         CONTAINER_PORT = '80'
     }
@@ -34,7 +34,13 @@ pipeline {
         stage('健康检查') {
             agent any
             steps {
-                sh 'sleep 5 && docker exec $CONTAINER_NAME curl -f http://localhost:$CONTAINER_PORT/ || (docker logs $CONTAINER_NAME && exit 1)'
+                sh 'sleep 15 && docker exec $CONTAINER_NAME curl -f http://localhost:$CONTAINER_PORT/ || (docker logs $CONTAINER_NAME && exit 1)'
+            }
+        }
+        stage('清理旧镜像') {
+            agent any
+            steps {
+                sh 'docker image prune -af --filter "until=168h" || true'
             }
         }
     }