feat: Agent采集uptime, 后端持久化kernel/uptime/diskIO, 前端磁盘BPS+IOPS展示

- Agent: system.go 添加 readUptime(), SystemStat 携带 Uptime
- Backend: Server 模型新增 Kernel 字段, ReceiveReport 持久化 kernel+uptime
- Backend: /agent/latest 返回 kernel/uptime/port_info/disk_io_info/disk_total
- Frontend: 磁盘监控改为 BPS+IOPS (4张卡片), 系统信息修复内核/运行时长/监听端口/磁盘容量
- 图表单位从 MB/s 改为 KB/s, 添加 formatBPS 工具函数

backend/internal/api/handlers/server_batch.go

@@ -14,7 +14,7 @@ import (
 // 批量操作域：批量导入 + 批量删除 // Logan.Li
 
 // BatchCreateServers 批量导入服务器 // Logan.Li
-// 接收 {servers:[...], region_id, auth_type}，逐条校验并创建，跳过重复（主机名或IP已存在）
+// 接收 {servers:[...], region_id, auth_type, credential_id}，逐条校验并创建，跳过重复（主机名或IP已存在）
 func (h *ServerHandler) BatchCreateServers(c *gin.Context) {
 	var req models.BatchCreateServerRequest
 	if err := c.ShouldBindJSON(&req); err != nil {
@@ -30,6 +30,28 @@ func (h *ServerHandler) BatchCreateServers(c *gin.Context) {
 		authType = "password"
 	}
 
+	// 如果指定了凭据，提前解密 // Logan.Li
+	var decryptedPwd, decryptedKey string
+	if req.CredentialID != nil && *req.CredentialID > 0 {
+		var cred models.Credential
+		if err := h.db.First(&cred, *req.CredentialID).Error; err != nil {
+			c.JSON(http.StatusBadRequest, models.Response{Code: 400, Message: "凭据不存在"})
+			return
+		}
+		plain, err := h.crypt.Decrypt(cred.Content)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, models.Response{Code: 500, Message: "凭据解密失败"})
+			return
+		}
+		if cred.Type == "ssh_key" {
+			decryptedKey = plain
+			authType = "key"
+		} else {
+			decryptedPwd = plain
+			authType = "password"
+		}
+	}
+
 	result := models.BatchCreateResult{Errors: []string{}}
 	for i, item := range req.Servers {
 		hostname := strings.TrimSpace(item.Hostname)
@@ -63,6 +85,8 @@ func (h *ServerHandler) BatchCreateServers(c *gin.Context) {
 			Port:     port,
 			Username: username,
 			AuthType: authType,
+			Password: decryptedPwd,
+			SSHKey:   decryptedKey,
 			OS:       item.OS,
 			CPU:      item.CPU,
 			Memory:   item.Memory * 1024, // GB → MB
@@ -111,7 +135,13 @@ func (h *ServerHandler) BatchDeleteServers(c *gin.Context) {
 	var servers []models.Server
 	h.db.Where("id IN ?", req.IDs).Find(&servers)
 
-	if err := h.db.Delete(&models.Server{}, req.IDs).Error; err != nil {
+	// 硬删除：先清理每台服务器的 Agent 上报和聚合数据
+	for _, s := range servers {
+		h.db.Unscoped().Where("hostname = ?", s.Hostname).Delete(&models.AgentReport{})
+		h.db.Unscoped().Where("hostname = ?", s.Hostname).Delete(&models.MetricsAggregate{})
+	}
+
+	if err := h.db.Unscoped().Delete(&models.Server{}, req.IDs).Error; err != nil {
 		c.JSON(http.StatusInternalServerError, models.Response{
 			Code:    500,
 			Message: "删除失败",
@@ -126,6 +156,6 @@ func (h *ServerHandler) BatchDeleteServers(c *gin.Context) {
 
 	c.JSON(http.StatusOK, models.Response{
 		Code:    200,
-		Message: "删除成功",
+		Message: "服务器已彻底删除",
 	})
 }