Fix alternate key creation: include required DisplayName in payload

The EntityKeyMetadata API requires a DisplayName with localized labels.
Uses the key_name as the display label by default.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: tpellissier

src/PowerPlatform/Dataverse/data/_odata.py

@@ -1519,6 +1519,21 @@ def _create_alternate_key(self, table_schema_name: str, key_name: str, columns:
         payload = {
             "SchemaName": key_name,
             "KeyAttributes": columns,
+            "DisplayName": {
+                "@odata.type": "Microsoft.Dynamics.CRM.Label",
+                "LocalizedLabels": [
+                    {
+                        "@odata.type": "Microsoft.Dynamics.CRM.LocalizedLabel",
+                        "Label": key_name,
+                        "LanguageCode": 1033,
+                    }
+                ],
+                "UserLocalizedLabel": {
+                    "@odata.type": "Microsoft.Dynamics.CRM.LocalizedLabel",
+                    "Label": key_name,
+                    "LanguageCode": 1033,
+                },
+            },
         }
         r = self._request("post", url, json=payload)
         metadata_id = self._extract_id_from_header(r.headers.get("OData-EntityId"))