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/models/user.go

@@ -3,7 +3,6 @@ package models
 import (
 	"time"
 
-	"gorm.io/gorm"
 )
 
 // User 用户模型
@@ -21,7 +20,6 @@ type User struct {
 	LastLogin  *time.Time     `json:"last_login"`
 	CreatedAt  time.Time      `json:"created_at"`
 	UpdatedAt  time.Time      `json:"updated_at"`
-	DeletedAt  gorm.DeletedAt `gorm:"index" json:"-"`
 
 	// 关联
 	Roles []Role `gorm:"many2many:user_roles;" json:"roles,omitempty"`
@@ -29,7 +27,7 @@ type User struct {
 
 // TableName 表名
 func (User) TableName() string {
-	return "users"
+	return "iam_users"
 }
 
 // Role 角色模型
@@ -41,7 +39,6 @@ type Role struct {
 	Status      int            `gorm:"default:1" json:"status"`
 	CreatedAt   time.Time      `json:"created_at"`
 	UpdatedAt   time.Time      `json:"updated_at"`
-	DeletedAt   gorm.DeletedAt `gorm:"index" json:"-"`
 
 	// 关联
 	Permissions []Permission `gorm:"many2many:role_permissions;" json:"permissions,omitempty"`
@@ -49,7 +46,7 @@ type Role struct {
 
 // TableName 表名
 func (Role) TableName() string {
-	return "roles"
+	return "iam_roles"
 }
 
 // Permission 权限模型
@@ -65,12 +62,11 @@ type Permission struct {
 	Status    int            `gorm:"default:1" json:"status"`
 	CreatedAt time.Time      `json:"created_at"`
 	UpdatedAt time.Time      `json:"updated_at"`
-	DeletedAt gorm.DeletedAt `gorm:"index" json:"-"`
 }
 
 // TableName 表名
 func (Permission) TableName() string {
-	return "permissions"
+	return "iam_permissions"
 }
 
 // LoginRequest 登录请求
@@ -143,4 +139,4 @@ type LDAPConfig struct {
 	UpdatedAt     time.Time `json:"updated_at"`
 }
 
-func (LDAPConfig) TableName() string { return "ldap_configs" }
+func (LDAPConfig) TableName() string { return "iam_ldap_configs" }