fix(BA-5830): propagate AppConfigGQL/AppConfigFragmentGQL import-cycle fix

Carry the BA-5829 `strawberry.lazy()` fix through this branch so the
merged-view AppConfig type doesn't eagerly load
`app_config_fragment.types.node` (which would re-enter
`app_config.types` while it is still initializing).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: jopemachine

src/ai/backend/manager/api/gql/app_config/types/node.py

@@ -2,9 +2,12 @@
 
 from __future__ import annotations
 
-from typing import Any
+from typing import TYPE_CHECKING, Annotated
 from uuid import UUID
 
+import strawberry
+from strawberry.scalars import JSON
+
 from ai.backend.common.dto.manager.v2.app_config.response import AppConfigNode
 from ai.backend.common.meta.meta import NEXT_RELEASE_VERSION
 from ai.backend.manager.api.gql.decorators import (
@@ -45,6 +48,6 @@ class AppConfigGQL(PydanticOutputMixin[AppConfigNode]):
     ] = gql_field(
         description="Contributing fragments in merge order (low → high).",
     )
-    config: dict[str, Any] | None = gql_field(
+    config: JSON | None = gql_field(
         description="Deep-merged configuration, or null when every fragment is empty.",
     )