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/alert_v2.go

@@ -94,7 +94,7 @@ type AlertRuleV2 struct {
 
 // TableName 指定表名
 func (AlertRuleV2) TableName() string {
-	return "alert_rules_v2"
+	return "monitor_alert_rules_v2"
 }
 
 // AlertCondition 告警条件定义
@@ -109,6 +109,11 @@ type AlertCondition struct {
 	Window     int       `json:"window"`      // 条件级聚合窗口
 }
 
+// TableName 指定表名
+func (AlertCondition) TableName() string {
+	return "monitor_alert_conditions"
+}
+
 // AlertConditionGroup 告警条件组
 type AlertConditionGroup struct {
 	Conditions []AlertCondition `json:"conditions"`   // 条件列表
@@ -159,7 +164,7 @@ type AlertNotifyTemplate struct {
 
 // TableName 指定表名
 func (AlertNotifyTemplate) TableName() string {
-	return "alert_notify_templates"
+	return "monitor_alert_notify_templates"
 }
 
 // TemplateVariable 模板变量定义
@@ -209,7 +214,7 @@ type AlertUpgrade struct {
 
 // TableName 指定表名
 func (AlertUpgrade) TableName() string {
-	return "alert_upgrades"
+	return "monitor_alert_upgrades"
 }
 
 // AlertUpgradeRule 告警升级规则
@@ -235,7 +240,7 @@ type AlertUpgradeRecord struct {
 
 // TableName 指定表名
 func (AlertUpgradeRecord) TableName() string {
-	return "alert_upgrade_records"
+	return "monitor_alert_upgrade_records"
 }
 
 // ============================================
@@ -278,7 +283,7 @@ type AlertSilence struct {
 
 // TableName 指定表名
 func (AlertSilence) TableName() string {
-	return "alert_silences"
+	return "monitor_alert_silences"
 }
 
 // AlertSilenceMatcher 静默匹配条件
@@ -349,7 +354,7 @@ type AlertEventV2 struct {
 
 // TableName 指定表名
 func (AlertEventV2) TableName() string {
-	return "alert_events_v2"
+	return "monitor_alert_events_v2"
 }
 
 // AlertRuleV2CreateRequest 告警规则创建请求