fix(BA-5830): break import cycle by lightening app_config_fragment package init

Carry the BA-5832 cycle fix through this branch: empty
`app_config_fragment/__init__.py` and route schema.py through the
submodule paths directly so `app_config.types.bulk_payloads` no longer
re-enters a partially-initialized `app_config.types` module via the
resolver.

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

Author: jopemachine

src/ai/backend/manager/api/gql/app_config_fragment/__init__.py

@@ -1,38 +1,9 @@
-"""AppConfigFragment GraphQL API package."""
+"""AppConfigFragment GraphQL API package.
 
-from .resolver import (
-    admin_app_config_fragments,
-    admin_bulk_create_app_config_fragments,
-    admin_bulk_purge_app_config_fragments,
-    admin_bulk_update_app_config_fragments,
-    app_config_fragment,
-    my_bulk_create_app_config_fragments,
-    my_bulk_update_app_config_fragments,
-)
-from .types import (
-    AppConfigFragmentFilterGQL,
-    AppConfigFragmentGQL,
-    AppConfigFragmentKeyInputGQL,
-    AppConfigFragmentOrderByGQL,
-    AppConfigFragmentOrderFieldGQL,
-    AppConfigScopeTypeGQL,
-)
-
-__all__ = [
-    # Queries — scope-bound list belongs on DomainV2 / UserV2 child fields
-    "app_config_fragment",
-    "admin_app_config_fragments",
-    # Bulk mutations
-    "admin_bulk_create_app_config_fragments",
-    "admin_bulk_update_app_config_fragments",
-    "admin_bulk_purge_app_config_fragments",
-    "my_bulk_create_app_config_fragments",
-    "my_bulk_update_app_config_fragments",
-    # Types
-    "AppConfigFragmentGQL",
-    "AppConfigScopeTypeGQL",
-    "AppConfigFragmentFilterGQL",
-    "AppConfigFragmentOrderByGQL",
-    "AppConfigFragmentOrderFieldGQL",
-    "AppConfigFragmentKeyInputGQL",
-]
+Resolver and type names are re-exported by ``schema.py`` directly via
+their submodules to keep this package's ``__init__`` import-light: a
+top-level ``from app_config_fragment import ...`` would otherwise drag
+in the mutation resolvers, which back-import from
+``app_config.types.bulk_payloads`` and form an import cycle when
+``AppConfigGQL`` is loading.
+"""

src/ai/backend/manager/api/gql/schema.py

@@ -20,15 +20,17 @@
     my_app_configs,
     public_app_config_fragments,
 )
-from .app_config_fragment import (
-    admin_app_config_fragments,
+from .app_config_fragment.resolver.mutation import (
     admin_bulk_create_app_config_fragments,
     admin_bulk_purge_app_config_fragments,
     admin_bulk_update_app_config_fragments,
-    app_config_fragment,
     my_bulk_create_app_config_fragments,
     my_bulk_update_app_config_fragments,
 )
+from .app_config_fragment.resolver.query import (
+    admin_app_config_fragments,
+    app_config_fragment,
+)
 from .app_config_policy import (
     admin_bulk_create_app_config_policies,
     admin_bulk_purge_app_config_policies,