fix: 服务 changed 状态以本地/云端版本比对为准，不依赖 manifest 的 changed 字段

manifest.changed 是 Jenkins 构建时标记的，表示"本次 release 有改动"，
不能反映私有部署是否需要更新。改为 current != latest 比对，
避免 current==latest 时误报"有更新"。

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tenant-service/src/main/java/com/xuqm/tenant/service/SystemUpdateService.java

@@ -310,8 +310,10 @@ public class SystemUpdateService {
             Object remoteSvc = remoteServices.get(manifestKey);
             if (remoteSvc instanceof Map) {
                 Map<String, Object> rMap = (Map<String, Object>) remoteSvc;
-                svcInfo.put("latest", rMap.getOrDefault("version", ""));
-                svcInfo.put("changed", rMap.getOrDefault("changed", false));
+                String latestVer = (String) rMap.getOrDefault("version", "");
+                String currentVer = localVersions.get(svc);
+                svcInfo.put("latest", latestVer);
+                svcInfo.put("changed", !latestVer.isEmpty() && !"unknown".equals(latestVer) && !currentVer.equals(latestVer));
             } else {
                 svcInfo.put("latest", "");
                 svcInfo.put("changed", false);