fix(BA-5829): use strawberry JSON scalar for opaque config payloads

Strawberry's schema builder can't resolve `dict[str, Any]` to a GraphQL
output/input type and fails the manager startup with `AppConfigFragment
fields cannot be resolved. Unexpected type 'dict[str, typing.Any]'`.
Switch the three opaque payload fields (`AppConfigGQL.config`,
`AppConfigFragmentGQL.extra_config`, and the bulk-input
`extra_config`) to `strawberry.scalars.JSON`, matching how
`service_catalog`, `agent`, `deployment`, and `notification` already
expose JSON-shaped fields.

Author: jopemachine

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

@@ -2,9 +2,10 @@
 
 from __future__ import annotations
 
-from typing import Any
 from uuid import UUID
 
+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.app_config_fragment.types.node import AppConfigFragmentGQL
@@ -34,6 +35,6 @@ class AppConfigGQL(PydanticOutputMixin[AppConfigNode]):
     fragments: list[AppConfigFragmentGQL] = 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.",
     )

src/ai/backend/manager/api/gql/app_config_fragment/types/bulk_inputs.py

@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-from typing import Any
+from strawberry.scalars import JSON
 
 from ai.backend.common.dto.manager.v2.app_config_fragment.request import (
     AdminAppConfigFragmentItemInput as AdminItemInputDTO,
@@ -46,7 +46,7 @@
 )
 class AdminAppConfigFragmentItemInputGQL(PydanticInputMixin[AdminItemInputDTO]):
     key: AppConfigFragmentKeyInputGQL = gql_field(description="Natural-key identifier.")
-    extra_config: dict[str, Any] = gql_field(description="Raw configuration payload.")
+    extra_config: JSON = gql_field(description="Raw configuration payload.")
 
 
 @gql_pydantic_input(
@@ -91,7 +91,7 @@ class AdminBulkPurgeAppConfigFragmentInputGQL(PydanticInputMixin[AdminBulkPurgeI
 )
 class MyAppConfigFragmentItemInputGQL(PydanticInputMixin[MyItemInputDTO]):
     name: str = gql_field(description="Policy name.")
-    extra_config: dict[str, Any] = gql_field(description="Raw configuration payload.")
+    extra_config: JSON = gql_field(description="Raw configuration payload.")
 
 
 @gql_pydantic_input(

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

@@ -3,9 +3,10 @@
 from __future__ import annotations
 
 from datetime import datetime
-from typing import Any
 from uuid import UUID
 
+from strawberry.scalars import JSON
+
 from ai.backend.common.dto.manager.v2.app_config_fragment.response import AppConfigFragmentNode
 from ai.backend.common.dto.manager.v2.app_config_fragment.types import AppConfigScopeType
 from ai.backend.common.meta.meta import NEXT_RELEASE_VERSION
@@ -41,7 +42,7 @@ class AppConfigFragmentGQL(PydanticOutputMixin[AppConfigFragmentNode]):
     scope_type: AppConfigScopeType = gql_field(description="Scope type.")
     scope_id: str = gql_field(description="Scope id.")
     name: str = gql_field(description="Policy name (FK to app_config_policies).")
-    extra_config: dict[str, Any] | None = gql_field(
+    extra_config: JSON | None = gql_field(
         description="Raw configuration payload, or null."
     )
     created_at: datetime = gql_field(description="Creation timestamp.")