Render blurhashes in Mastodon API

lib/pleroma/web/mastodon_api/views/status_view.ex

@@ -435,7 +435,8 @@ def render("attachment.json", %{attachment: attachment}) do
       text_url: href,
       type: type,
       description: attachment["name"],
-      pleroma: %{mime_type: media_type}
+      pleroma: %{mime_type: media_type},
+      blurhash: attachment["blurhash"]
     }
   end
 

test/pleroma/web/mastodon_api/views/status_view_test.exs

@@ -420,6 +420,7 @@ test "attachments" do
           "href" => "someurl"
         }
       ],
+      "blurhash" => "UJJ8X[xYW,%Jtq%NNFbXB5j]IVM|9GV=WHRn",
       "uuid" => 6
     }
 
@@ -431,7 +432,8 @@ test "attachments" do
       preview_url: "someurl",
       text_url: "someurl",
       description: nil,
-      pleroma: %{mime_type: "image/png"}
+      pleroma: %{mime_type: "image/png"},
+      blurhash: "UJJ8X[xYW,%Jtq%NNFbXB5j]IVM|9GV=WHRn"
     }
 
     api_spec = Pleroma.Web.ApiSpec.spec()