Add optional order property for UI ordering (Issue #27)

v1/specification/json-schemas/gdd/README.md

@@ -168,6 +168,7 @@ All properties share these definitions: ([JSON-schema definition](https://json-s
   "gddType": string, // [Optional unless required by GDD Type] A string containing the GDD Type name, see below
   "gddOptions": object, // [Optional unless required by GDD Type] An object containing options for a certain GDD Type, see below
   "hidden": boolean // [Optional] When true, exclude this property's value when building a label/display name for the graphic in a GUI. Default false.
+  "order": number // [Optional] Hint for UI ordering; lower means earlier
 }
 ```
 #### The `type` property
@@ -450,6 +451,37 @@ Example:
 }
 ```
 
+## Property order
+
+To provide a stable and author-controlled ordering in UIs, each property MAY define an `order` value:
+
+- Properties with a lower `order` value SHOULD be rendered before properties with a higher `order` value.
+- Properties with an `order` value SHOULD be rendered before properties without an `order` value.
+- Properties without an `order` value MAY be ordered in an implementation-defined way.
+
+Example:
+
+```json
+{
+  "type": "object",
+  "properties": {
+    "title": {
+      "type": "string",
+      "order": 1
+    },
+    "subtitle": {
+      "type": "string",
+      "order": 2
+    },
+    "internalNotes": {
+      "type": "string"
+    }
+  }
+}
+```
+
+In a GUI, `title` SHOULD be displayed before `subtitle`, while `internalNotes` (which has no `order`) can be placed after them in an implementation-defined position.
+
 ## For GUI Developers
 
 ### Getting started

v1/specification/json-schemas/gdd/object.json

@@ -23,6 +23,10 @@
     "hidden": {
       "type": "boolean",
       "description": "When true, the value of this property SHOULD NOT be included when labelling the graphic in a GUI (e.g. in playout or automation UIs). Default is false. Used to keep labels concise by excluding technical or less meaningful fields."
+    },
+    "order": {
+      "type": "number",
+      "description": "For UI ordering, lower values should be displayed first"
     }
   },
   "required": ["type"],