feat(audit): F1+F2 告警静默规则标记完成 + 审计日志CSV导出实现

F1 告警静默规则 [done]:
- 后端 alert_silence.go: CRUD + Toggle (onetime/daily/weekly 三模式)
- 告警引擎 isSilenced 集成 (alert_engine.go)
- 前端 SilenceRuleTab + SilenceDialog
- 路由 /alerts/silences 已注册

F2 审计日志导出 [done]:
- 重写 ExportAuditLogs: 真正的 CSV 导出 (encoding/csv + UTF-8 BOM)
- 支持 module/action/username/startTime/endTime 筛选
- 导出限制 10000 条防溢出，自动记录审计日志
- JSON 格式向后兼容 (format=json)
- 前端 exportLogs 传递查询参数

同时包含累积的前期工作:
- 目录重构 internal/ -> controller/model/router (v0.55-v0.57)
- 后端分层架构 dto/repository/service/utils
- 审计模块全功能 (终端审计/操作审计/登录日志)
- asciicast v2 录制格式
- SFTP 文件浏览器
- StatStrip 紧凑统计条
- 在线会话自动刷新
- LiveMonitor WebSocket 诊断修复

验证: go build ✅ | npm run build ✅ | Docker 部署 ✅ | 10 回归端点 ✅ | CSV 导出 ✅ | 静默 CRUD ✅

backend/controller/alert.go

@@ -0,0 +1,133 @@
+package controller
+
+import (
+	"encoding/json"
+	"net/http"
+	"strconv"
+
+	"ezops/model"
+
+	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
+)
+
+// 告警事件处理 + AlertHandler 定义（规则见 alert_rules.go，渠道见 alert_channels.go） // Logan.Li
+
+// AlertHandler 告警处理器
+type AlertHandler struct {
+	db *gorm.DB
+}
+
+// NewAlertHandler 创建告警处理器
+func NewAlertHandler(db *gorm.DB) *AlertHandler {
+	return &AlertHandler{db: db}
+}
+
+// ListAlerts 获取告警事件列表
+// @Summary 获取告警事件列表
+// @Description 获取所有告警事件列表
+// @Tags 告警
+// @Produce json
+// @Security Bearer
+// @Param page query int false "页码"
+// @Param page_size query int false "每页数量"
+// @Param status query string false "状态过滤"
+// @Param severity query string false "级别过滤"
+// @Success 200 {object} model.Response{data=model.ListResponse}
+// @Router /alerts [get]
+func (h *AlertHandler) ListAlerts(c *gin.Context) {
+	var query model.PageQuery
+	c.ShouldBindQuery(&query)
+
+	db := h.db.Model(&model.AlertEvent{}).Preload("Rule")
+
+	// 状态过滤
+	if status := c.Query("status"); status != "" {
+		db = db.Where("status = ?", status)
+	}
+
+	// 级别过滤
+	if severity := c.Query("severity"); severity != "" {
+		db = db.Where("severity = ?", severity)
+	}
+
+	var total int64
+	db.Count(&total)
+
+	var alerts []model.AlertEvent
+	db.Order("created_at DESC").
+		Offset(query.GetOffset()).
+		Limit(query.GetLimit()).
+		Find(&alerts)
+
+	c.JSON(http.StatusOK, model.Response{
+		Code:    200,
+		Message: "success",
+		Data: model.ListResponse{
+			List:  alerts,
+			Total: total,
+		},
+	})
+}
+
+// AcknowledgeAlert 确认告警
+// @Summary 确认告警
+// @Description 确认告警事件
+// @Tags 告警
+// @Accept json
+// @Produce json
+// @Security Bearer
+// @Param id path int true "告警ID"
+// @Param request body model.AcknowledgeAlertRequest true "确认请求"
+// @Success 200 {object} model.Response{data=model.AlertEvent}
+// @Router /alerts/{id}/ack [post]
+func (h *AlertHandler) AcknowledgeAlert(c *gin.Context) {
+	id, _ := strconv.Atoi(c.Param("id"))
+
+	var req model.AcknowledgeAlertRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, model.Response{
+			Code:    400,
+			Message: "请求参数错误",
+		})
+		return
+	}
+
+	var alert model.AlertEvent
+	if err := h.db.First(&alert, id).Error; err != nil {
+		c.JSON(http.StatusNotFound, model.Response{
+			Code:    404,
+			Message: "告警不存在",
+		})
+		return
+	}
+
+	alert.Acknowledged = true
+	// alert.AcknowledgedBy = middleware.GetUserID(c)
+	// now := time.Now()
+	// alert.AcknowledgedAt = &now
+
+	if err := h.db.Save(&alert).Error; err != nil {
+		c.JSON(http.StatusInternalServerError, model.Response{
+			Code:    500,
+			Message: "确认失败",
+		})
+		return
+	}
+
+	c.JSON(http.StatusOK, model.Response{
+		Code:    200,
+		Message: "确认成功",
+		Data:    alert,
+	})
+}
+
+// toJSON serializes a value to JSON string. Returns empty string on error.
+// 包级辅助函数，供 alert_rules.go 等同包文件复用 // Logan.Li
+func toJSON(v interface{}) string {
+	b, err := json.Marshal(v)
+	if err != nil {
+		return ""
+	}
+	return string(b)
+}