fix(gooddata-sdk): keep isHiddenFromKda on declarative metrics

CatalogDeclarativeMetric did not declare is_hidden_from_kda. The
generated DeclarativeMetric gained the field when the API client was
regenerated, but the SDK attrs class was not updated, and cattrs drops
keys a class does not declare. So loading a metric layout from disk or
the server lost the flag silently, and every SDK put sent the metric
without it: a git deploy could never set it, and a load-then-put wiped
a flag set in the UI.

Declare the field on the metric class only; the other analytics
classes share CatalogAnalyticsBase but their generated models have no
such field. An unset field stays None and is not sent, so existing
layouts and cassettes are unchanged. A round-trip test covers true,
false and an absent key through disk and to_api().

jira: GDAI-2630
risk: low

Author: tychtjan

packages/gooddata-sdk/src/gooddata_sdk/catalog/workspace/declarative_model/workspace/analytics_model/analytics_model.py

@@ -331,6 +331,8 @@ def client_class() -> type[DeclarativeFilterContext]:
 
 @define(kw_only=True)
 class CatalogDeclarativeMetric(CatalogAnalyticsBase):
+    is_hidden_from_kda: bool | None = None
+
     @staticmethod
     def client_class() -> type[DeclarativeMetric]:
         return DeclarativeMetric

packages/gooddata-sdk/tests/catalog/unit_tests/test_declarative_analytics_metrics.py

@@ -0,0 +1,34 @@
+# (C) 2026 GoodData Corporation
+"""Unit test: a metric's ``isHiddenFromKda`` survives the declarative round trip."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+import pytest
+from gooddata_sdk.catalog.workspace.declarative_model.workspace.analytics_model.analytics_model import (
+    CatalogDeclarativeAnalyticsLayer,
+)
+
+_METRIC = {"id": "bmk_w_fraud_charged_back", "title": "BMK", "content": {"format": "#,##0", "maql": "SELECT 1"}}
+
+
+@pytest.mark.parametrize(
+    ("extra", "expected"),
+    [
+        ({"isHiddenFromKda": True}, True),
+        ({"isHiddenFromKda": False}, False),
+        ({}, None),
+    ],
+    ids=["hidden", "explicit-visible", "absent"],
+)
+def test_declarative_metric_is_hidden_from_kda_survives_round_trip(
+    tmp_path: Path, extra: dict, expected: bool | None
+) -> None:
+    layer = CatalogDeclarativeAnalyticsLayer.from_dict({"metrics": [{**_METRIC, **extra}]})
+
+    layer.store_to_disk(tmp_path)
+    reloaded = CatalogDeclarativeAnalyticsLayer.load_from_disk(tmp_path)
+
+    assert reloaded.metrics[0].is_hidden_from_kda is expected
+    assert reloaded.to_api().to_dict(camel_case=True)["metrics"][0] == {**_METRIC, **extra}