fix(backend): ensure total pages is at least 1

When there are no items, the total pages should be 1, not 0, as a page is still rendered.

Author: yashranjan1

internal/backend/crud/interfaces.go

@@ -38,7 +38,10 @@ type PaginationMetadata struct {
 }
 
 func CalculatePagination(total int64, limit, offset int) PaginationMetadata {
-	totalPages := int((total + int64(limit) - 1) / int64(limit)) // Ceiling division
+	totalPages := 1
+	if total > 0 {
+		totalPages = int((total + int64(limit) - 1) / int64(limit)) // Ceiling division
+	}
 	currentPage := (offset / limit) + 1
 	hasNext := (offset + limit) < int(total)
 	hasPrev := offset > 0