feat: add date range filter to marketing list API

Added start_date, end_date, and filter_by query parameters to the
GET /api/marketing/ endpoint. Users can now filter marketing records
by a date range using either so_date (Sales Order date, default) or
created_at as the target column.

Changes:
- validation: added StartDate, EndDate (YYYY-MM-DD format), and
  FilterBy (oneof: so_date, created_at) to DeliveryOrderQuery struct
- controller: parse the three new query params in GetAll handler
- service: apply >=start / <end+1day date range filter in the query
  modifier using the existing utils.ParseDateRangeForQuery helper

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

internal/modules/marketing/controllers/deliveryorder.controller.go

@@ -75,6 +75,9 @@ func (u *DeliveryOrdersController) GetAll(c *fiber.Ctx) error {
 		WarehouseID:           uint(c.QueryInt("warehouse_id", 0)),
 		SortBy:                sortBy,
 		SortOrder:             sortOrder,
+		StartDate:             strings.TrimSpace(c.Query("start_date", "")),
+		EndDate:               strings.TrimSpace(c.Query("end_date", "")),
+		FilterBy:              strings.TrimSpace(c.Query("filter_by", "")),
 	}
 
 	if isAllExcelExportRequest(c) {