feat(ops): 添加高级设置API支持

- 新增OpsAdvancedSettings数据模型
- 支持数据保留策略配置（错误日志、分钟级指标、小时级指标）
- 支持数据聚合开关配置
- 添加GET/PUT /admin/ops/advanced-settings接口
- 添加配置校验和默认值处理

相关文件：
- backend/internal/service/ops_settings_models.go
- backend/internal/service/ops_settings.go
- backend/internal/handler/admin/ops_settings_handler.go
- backend/internal/server/routes/admin.go
- backend/internal/service/domain_constants.go

backend/internal/handler/admin/ops_settings_handler.go

@@ -101,3 +101,49 @@ func (h *OpsHandler) UpdateAlertRuntimeSettings(c *gin.Context) {
 	response.Success(c, updated)
 }
 
+// GetAdvancedSettings returns Ops advanced settings (DB-backed).
+// GET /api/v1/admin/ops/advanced-settings
+func (h *OpsHandler) GetAdvancedSettings(c *gin.Context) {
+	if h.opsService == nil {
+		response.Error(c, http.StatusServiceUnavailable, "Ops service not available")
+		return
+	}
+	if err := h.opsService.RequireMonitoringEnabled(c.Request.Context()); err != nil {
+		response.ErrorFrom(c, err)
+		return
+	}
+
+	cfg, err := h.opsService.GetOpsAdvancedSettings(c.Request.Context())
+	if err != nil {
+		response.Error(c, http.StatusInternalServerError, "Failed to get advanced settings")
+		return
+	}
+	response.Success(c, cfg)
+}
+
+// UpdateAdvancedSettings updates Ops advanced settings (DB-backed).
+// PUT /api/v1/admin/ops/advanced-settings
+func (h *OpsHandler) UpdateAdvancedSettings(c *gin.Context) {
+	if h.opsService == nil {
+		response.Error(c, http.StatusServiceUnavailable, "Ops service not available")
+		return
+	}
+	if err := h.opsService.RequireMonitoringEnabled(c.Request.Context()); err != nil {
+		response.ErrorFrom(c, err)
+		return
+	}
+
+	var req service.OpsAdvancedSettings
+	if err := c.ShouldBindJSON(&req); err != nil {
+		response.BadRequest(c, "Invalid request body")
+		return
+	}
+
+	updated, err := h.opsService.UpdateOpsAdvancedSettings(c.Request.Context(), &req)
+	if err != nil {
+		response.Error(c, http.StatusBadRequest, err.Error())
+		return
+	}
+	response.Success(c, updated)
+}
+