fix(agent): 修复资产重复注册(每10s新建) + 批量删除400

agent 自动注册前按 hostname 显式查重（asset_servers.hostname 无 UNIQUE 索引，OnConflict 失效导致 Agent 每次上报都 INSERT 新记录，资产越来越多）。

批量删除 BatchDeleteServers 对齐前端 {ids} 格式（原期望裸 []uint 导致 ShouldBindJSON 解析失败 400）。

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

backend/controller/agent.go

@@ -163,43 +163,57 @@ func (h *AgentHandler) ReceiveReport(c *gin.Context) {
 		result = h.db.Exec(updateSQL2, args2...)
 	}
 
-	// 如果还是没匹配到 —— 自动注册新服务器（UPSERT 防重复）
+	// 如果还是没匹配到 —— 按 hostname 显式查重后再注册 // Logan.Li
+	// asset_servers.hostname 无 UNIQUE 索引，OnConflict 不可靠，故先 First 查重，
+	// 避免 Agent 每次上报（10s）都新建记录导致资产越来越多。
 	if result.RowsAffected == 0 {
 		osName := ""
 		if req.System != nil {
 			osName = req.System.OSVersion
 		}
-		newServer := model.Server{
-			Hostname:     req.Hostname,
-			IP:           matchIP,
-			Port:         22,
-			Username:     "root",
-			AuthType:     "password",
-			OS:           osName,
-			CPU:          req.CPU.CoreCount,
-			Memory:       memMB,
-			Disk:         diskGB,
-			Status:       "running",
-			AgentStatus:  "online",
-			AgentVersion: req.AgentVersion,
-			CPUUsage:     req.CPU.UsagePercent,
-			MemoryUsage:  req.Memory.UsagePercent,
-			DiskUsage:    diskAvg,
-		}
-		// ON DUPLICATE KEY UPDATE — 若 hostname 已存在则更新字段（防重复注册）
-		if err := h.db.Clauses(clause.OnConflict{
-			Columns: []clause.Column{{Name: "hostname"}},
-			DoUpdates: clause.AssignmentColumns([]string{
-				"ip", "os", "cpu", "memory", "disk",
-				"status", "agent_status",
-				"cpu_usage", "memory_usage", "disk_usage",
-				"updated_at",
-			}),
-		}).Create(&newServer).Error; err != nil {
-			fmt.Printf("[agent] 自动注册主机 %q (IP: %s) 失败: %v\n", req.Hostname, matchIP, err)
+		var existing model.Server
+		if h.db.Where("hostname = ?", req.Hostname).First(&existing).Error == nil {
+			// 已自动注册过 → 仅更新实时指标，不重复创建
+			h.db.Model(&existing).Updates(map[string]interface{}{
+				"ip": matchIP, "os": osName, "cpu": req.CPU.CoreCount,
+				"memory": memMB, "disk": diskGB, "status": "running",
+				"agent_status": "online", "agent_version": req.AgentVersion,
+				"cpu_usage": req.CPU.UsagePercent, "memory_usage": req.Memory.UsagePercent,
+				"disk_usage": diskAvg,
+			})
 		} else {
-			fmt.Printf("[agent] 自动注册新主机: %q (IP: %s, CPU=%d核, 内存=%dMB, 磁盘=%dGB, OS=%q)\n",
-				req.Hostname, matchIP, req.CPU.CoreCount, memMB, diskGB, osName)
+			// 真正的新主机 → 注册（OnConflict 作为并发双保险）
+			newServer := model.Server{
+				Hostname:     req.Hostname,
+				IP:           matchIP,
+				Port:         22,
+				Username:     "root",
+				AuthType:     "password",
+				OS:           osName,
+				CPU:          req.CPU.CoreCount,
+				Memory:       memMB,
+				Disk:         diskGB,
+				Status:       "running",
+				AgentStatus:  "online",
+				AgentVersion: req.AgentVersion,
+				CPUUsage:     req.CPU.UsagePercent,
+				MemoryUsage:  req.Memory.UsagePercent,
+				DiskUsage:    diskAvg,
+			}
+			if err := h.db.Clauses(clause.OnConflict{
+				Columns: []clause.Column{{Name: "hostname"}},
+				DoUpdates: clause.AssignmentColumns([]string{
+					"ip", "os", "cpu", "memory", "disk",
+					"status", "agent_status",
+					"cpu_usage", "memory_usage", "disk_usage",
+					"updated_at",
+				}),
+			}).Create(&newServer).Error; err != nil {
+				fmt.Printf("[agent] 自动注册主机 %q (IP: %s) 失败: %v\n", req.Hostname, matchIP, err)
+			} else {
+				fmt.Printf("[agent] 自动注册新主机: %q (IP: %s, CPU=%d核, 内存=%dMB, 磁盘=%dGB, OS=%q)\n",
+					req.Hostname, matchIP, req.CPU.CoreCount, memMB, diskGB, osName)
+			}
 		}
 	}
 

backend/controller/server_v2.go

@@ -169,11 +169,15 @@ func (h *ServerHandlerV2) BatchCreateServers(c *gin.Context) {
 }
 
 func (h *ServerHandlerV2) BatchDeleteServers(c *gin.Context) {
-	var ids []uint
-	if err := c.ShouldBindJSON(&ids); err != nil {
+	// 前端发 { ids: [...] }，对齐格式（原期望裸 []uint 导致解析失败 400） // Logan.Li
+	var req struct {
+		IDs []uint `json:"ids"`
+	}
+	if err := c.ShouldBindJSON(&req); err != nil || len(req.IDs) == 0 {
 		utils.BadRequest(c, "请求参数错误")
 		return
 	}
+	ids := req.IDs
 	// 清理关联数据
 	for _, id := range ids {
 		var s model.Server