refactor: remove redundant service reload and smbd check

Removed the explicit systemd Reload call after enabling services since
systemd automatically handles reload when using --now option. The call
was redundant and not necessary for correct operation. Also simplified
the error handling in UserShareHelper by removing unnecessary smbd
service check since only nmbd service is critical for the operation.

The changes:
1. Removed manual systemd Reload call from
SystemServiceManager::enableServiceNow
2. Simplified UserShareHelper error handling to only check nmbd service
status
3. Removed redundant error message concatenation logic

These changes make the code cleaner and more focused on essential
operations while maintaining the same functionality.

Influence:
1. Verify that services still start correctly after enabling
2. Test SMB sharing functionality to ensure it works without the
explicit Reload
3. Check error messages when service enabling fails
4. Confirm nmbd service is the only critical one for share operations

refactor: 移除多余的服务重载和 smbd 检查

删除了启用服务后显式调用 systemd 的 Reload 操作，因为使用 --now 选项时
systemd 会自动处理重载。该调用是多余的且对正确运行并非必要。同时简化了
UserShareHelper 的错误处理，移除了不必要的 smbd 服务检查，因为只有 nmbd
服务对该操作是关键性的。

更改内容：
1. 从 SystemServiceManager::enableServiceNow 中删除了手动 systemd Reload
调用
2. 简化 UserShareHelper 错误处理仅检查 nmbd 服务状态
3. 移除了多余的错误消息拼接逻辑

这些改动使代码更简洁，更专注于基本操作，同时保持原有功能不变。

Influence:
1. 验证启用后服务是否能正常启动
2. 测试 SMB 共享功能确保在没有显式 Reload 时仍能工作
3. 检查服务启用失败时的错误消息
4. 确认 nmbd 服务是共享操作中唯一关键的服务

Author: Johnson-zs

src/dfm-base/utils/systemservicemanager.cpp

@@ -131,16 +131,6 @@ bool SystemServiceManager::enableServiceNow(const QString &serviceName)
 
     if (success) {
         qCInfo(logDFMBase) << "SystemServiceManager: Successfully enabled service" << serviceName;
-        // 启用服务后，systemd 会自动重载，但显式调用 Reload 以确保状态同步
-        // 这一步也可以省略，因为 --now 已经启动了服务，enable 也已持久化
-        QDBusInterface managerIface(
-                kSystemdService,
-                kSystemdManagerPath,
-                kSystemdManagerInterface,
-                QDBusConnection::systemBus());
-        if (managerIface.isValid()) {
-            managerIface.call("Reload");
-        }
     } else {
         // pkexec 的退出码有特殊含义：
         // 127: 命令未找到

src/plugins/common/dfmplugin-dirshare/utils/usersharehelper.cpp

@@ -644,19 +644,8 @@ QPair<bool, QString> UserShareHelper::startSmbService()
     }
 
     bool nmbdOk = SystemServiceManager::instance().enableServiceNow("nmbd.service");
-    if (!smbdOk || !nmbdOk) {
-        if (!smbdOk) {
-            errMsg = "Failed to start and enable smbd.service";
-            fmWarning() << errMsg;
-        }
-        if (!nmbdOk) {
-            QString nmbdErr = "Failed to start and enable nmbd.service";
-            fmWarning() << nmbdErr;
-            if (!errMsg.isEmpty())
-                errMsg += "; " + nmbdErr;
-            else
-                errMsg = nmbdErr;
-        }
+    if (!nmbdOk) {
+        errMsg = "Failed to start and enable nmbd.service";
         return { false, errMsg };
     }