improvement: support new struct fields constraint

lib/ash_graphql.ex

@@ -680,13 +680,27 @@ defmodule AshGraphql do
         }
 
         case attribute.type do
-          Ash.Type.Map ->
-            if attribute.constraints[:fields] do
-              {source_resource, attribute}
+          type when type in [Ash.Type.Map, Ash.Type.Keyword, Ash.Type.Struct] ->
+            if fields = attribute.constraints[:fields] do
+              Enum.flat_map(fields, fn {name, config} ->
+                if AshGraphql.Resource.embedded?(config[:type]) do
+                  [
+                    {source_resource,
+                     %{
+                       attribute
+                       | type: config[:type],
+                         constraints: config[:constraints],
+                         name: :"#{attribute.name}_#{name}"
+                     }}
+                  ]
+                else
+                  []
+                end
+              end)
+            else
+              []
             end
 
-            []
-
           Ash.Type.Union ->
             attribute.constraints[:types]
             |> Kernel.||([])

lib/resource/resource.ex

@@ -2979,9 +2979,14 @@ defmodule AshGraphql.Resource do
       {types, fields} =
         Enum.reduce(constraints[:fields] || [], {[], []}, fn {name, attribute}, {types, fields} ->
           map_type? =
-            attribute[:type] in [:map, Ash.Type.Map] ||
+            attribute[:type] in [:map, Ash.Type.Map, :struct, Ash.Type.Struct] ||
               (Ash.Type.NewType.new_type?(attribute[:type]) &&
-                 Ash.Type.NewType.subtype_of(attribute[:type]) in [:map, Ash.Type.Map])
+                 Ash.Type.NewType.subtype_of(attribute[:type]) in [
+                   :map,
+                   Ash.Type.Map,
+                   :struct,
+                   Ash.Type.Struct
+                 ])
 
           if map_type? && attribute[:constraints] not in [nil, []] do
             nested_type_name =