feat(BA-5829): add AppConfigFragment + AppConfig GQL surface

Adds the GraphQL exposure for AppConfigFragment and the merged
AppConfig view (BEP-1052 §2 / §5).

Service / processor additions (only what the GQL layer needs that is
not already in BA-5827):
- Merged-view actions: get_user_app_config, search_user_app_configs,
  admin_search_app_configs (single-row + paginated reads of the
  computed AppConfig view).
- Service methods + processor wiring + supported_actions for those
  three actions.

Adapter additions:
- Merged-view methods: get_user_app_config / my_app_configs /
  admin_search_app_configs / public_app_config_fragments. `my_*`
  pulls the user from current_user() inside the adapter.
- Bulk-only `my` mutations: my_bulk_create / my_bulk_update —
  bulk admin variants are wired in BA-5827 already.

DTO additions:
- common/dto/manager/v2/app_config/* — AppConfigNode,
  GetUserAppConfigInput / Payload, SearchAppConfigsInput / Payload,
  SearchMyAppConfigsInput, BulkCreate/UpdateMyAppConfigFragmentsPayload
  (the my-bulk payloads live here because they carry AppConfigNode).

GraphQL:
- app_config package: AppConfigGQL, my/admin/public root resolvers.
- app_config_fragment package: scope-bound + admin queries, bulk-only
  mutations (admin + my variants), AppConfigFragmentGQL +
  AppConfigScopeTypeGQL + filter/order/key inputs.
- DataLoader: app_config_fragment_loader for N+1 batching.
- schema.py: register the new root queries / mutations.

Resolves BA-5829.

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

Author: jopemachine

src/ai/backend/common/dto/manager/v2/app_config/__init__.py

@@ -1,29 +1,39 @@
 """
-App configuration DTOs v2 for Manager API.
+AppConfig (merged view) DTOs v2 for Manager API (BEP-1052 §5).
 """
 
-from ai.backend.common.dto.manager.v2.app_config.request import (
-    DeleteDomainConfigInput,
-    DeleteUserConfigInput,
-    UpsertDomainConfigInput,
-    UpsertUserConfigInput,
+from .request import (
+    AppConfigFilter,
+    AppConfigOrder,
+    GetUserAppConfigInput,
+    SearchAppConfigsInput,
+    SearchMyAppConfigsInput,
 )
-from ai.backend.common.dto.manager.v2.app_config.response import (
+from .response import (
     AppConfigNode,
-    DeleteDomainConfigPayload,
-    DeleteUserConfigPayload,
-    UpsertDomainConfigPayloadDTO,
-    UpsertUserConfigPayloadDTO,
+    BulkCreateMyAppConfigFragmentsPayload,
+    BulkUpdateMyAppConfigFragmentsPayload,
+    GetUserAppConfigPayload,
+    SearchAppConfigsPayload,
+)
+from .types import (
+    AppConfigOrderField,
+    AppConfigScopeType,
+    OrderDirection,
 )
 
 __all__ = (
-    "DeleteDomainConfigInput",
-    "DeleteUserConfigInput",
-    "UpsertDomainConfigInput",
-    "UpsertUserConfigInput",
+    "AppConfigFilter",
     "AppConfigNode",
-    "DeleteDomainConfigPayload",
-    "DeleteUserConfigPayload",
-    "UpsertDomainConfigPayloadDTO",
-    "UpsertUserConfigPayloadDTO",
+    "AppConfigOrder",
+    "AppConfigOrderField",
+    "AppConfigScopeType",
+    "BulkCreateMyAppConfigFragmentsPayload",
+    "BulkUpdateMyAppConfigFragmentsPayload",
+    "GetUserAppConfigInput",
+    "GetUserAppConfigPayload",
+    "OrderDirection",
+    "SearchAppConfigsInput",
+    "SearchAppConfigsPayload",
+    "SearchMyAppConfigsInput",
 )

src/ai/backend/common/dto/manager/v2/app_config/request.py

@@ -1,55 +1,73 @@
 """
-Request DTOs for App Configuration v2.
+Request DTOs for AppConfig (merged view) DTO v2 (BEP-1052 §5).
 """
 
 from __future__ import annotations
 
-from typing import Any
 from uuid import UUID
 
 from pydantic import Field
 
 from ai.backend.common.api_handlers import BaseRequestModel
+from ai.backend.common.dto.manager.query import StringFilter, UUIDFilter
+
+from .types import AppConfigOrderField, OrderDirection
 
 __all__ = (
-    "DeleteDomainConfigInput",
-    "DeleteUserConfigInput",
-    "UpsertDomainConfigInput",
-    "UpsertUserConfigInput",
+    "AppConfigFilter",
+    "AppConfigOrder",
+    "GetUserAppConfigInput",
+    "SearchAppConfigsInput",
+    "SearchMyAppConfigsInput",
 )
 
 
-class UpsertDomainConfigInput(BaseRequestModel):
-    """Input for creating or updating domain-level app configuration."""
+class GetUserAppConfigInput(BaseRequestModel):
+    """Input for reading a single merged AppConfig for a target user
+    (admin path — the `my` variant resolves the user internally)."""
 
-    domain_name: str = Field(description="Domain name whose configuration will be upserted.")
-    extra_config: dict[str, Any] = Field(
-        description="Configuration data to store. Completely replaces existing configuration."
-    )
+    user_id: UUID = Field(description="Target user's UUID.")
+    name: str = Field(description="Policy / config name.")
 
 
-class UpsertUserConfigInput(BaseRequestModel):
-    """Input for creating or updating user-level app configuration."""
+class AppConfigFilter(BaseRequestModel):
+    """Filter for AppConfig merged-view search."""
 
-    extra_config: dict[str, Any] = Field(
-        description="Configuration data to store. Completely replaces existing configuration."
-    )
-    user_id: UUID | None = Field(
+    name: StringFilter | None = Field(default=None, description="Filter by policy name.")
+    user_id: UUIDFilter | None = Field(
         default=None,
-        description="User ID whose configuration will be upserted. Defaults to current user.",
+        description="Filter by target user id (admin cross-user search only).",
     )
 
 
-class DeleteDomainConfigInput(BaseRequestModel):
-    """Input for deleting domain-level app configuration."""
+class AppConfigOrder(BaseRequestModel):
+    """Order specification for AppConfig merged-view results."""
 
-    domain_name: str = Field(description="Domain name whose configuration will be deleted.")
+    field: AppConfigOrderField = Field(description="Field to order by.")
+    direction: OrderDirection = Field(default=OrderDirection.ASC, description="Order direction.")
 
 
-class DeleteUserConfigInput(BaseRequestModel):
-    """Input for deleting user-level app configuration."""
+class _AppConfigSearchInputBase(BaseRequestModel):
+    filter: AppConfigFilter | None = Field(default=None, description="Filter conditions.")
+    order: list[AppConfigOrder] | None = Field(default=None, description="Order specifications.")
+    first: int | None = Field(default=None, ge=1, description="Number of items from the start.")
+    after: str | None = Field(default=None, description="Cursor to paginate forward from.")
+    last: int | None = Field(default=None, ge=1, description="Number of items from the end.")
+    before: str | None = Field(default=None, description="Cursor to paginate backward from.")
+    limit: int | None = Field(default=None, ge=1, le=1000, description="Maximum items to return.")
+    offset: int | None = Field(default=None, ge=0, description="Number of items to skip.")
 
-    user_id: UUID | None = Field(
-        default=None,
-        description="User ID whose configuration will be deleted. Defaults to current user.",
-    )
+
+class SearchMyAppConfigsInput(_AppConfigSearchInputBase):
+    """Input for self-service merged-view search (`/v2/app-configs/my/search`).
+
+    The adapter pins the caller as the user scope; no `user_id` argument
+    is accepted here (BEP-1052 §5 — `filter.userId` is ignored).
+    """
+
+
+class SearchAppConfigsInput(_AppConfigSearchInputBase):
+    """Input for admin cross-user merged-view search.
+
+    Optional `filter.user_id` pins the search to a single user.
+    """

src/ai/backend/common/dto/manager/v2/app_config/response.py

@@ -1,49 +1,84 @@
 """
-Response DTOs for app_config DTO v2.
+Response DTOs for AppConfig (merged view) DTO v2 (BEP-1052 §5).
 """
 
 from __future__ import annotations
 
 from typing import Any
+from uuid import UUID
 
 from pydantic import Field
 
 from ai.backend.common.api_handlers import BaseResponseModel
+from ai.backend.common.dto.manager.v2.app_config_fragment.response import (
+    AppConfigFragmentBulkError,
+    AppConfigFragmentNode,
+)
 
 __all__ = (
     "AppConfigNode",
-    "DeleteDomainConfigPayload",
-    "DeleteUserConfigPayload",
-    "UpsertDomainConfigPayloadDTO",
-    "UpsertUserConfigPayloadDTO",
+    "BulkCreateMyAppConfigFragmentsPayload",
+    "BulkUpdateMyAppConfigFragmentsPayload",
+    "GetUserAppConfigPayload",
+    "SearchAppConfigsPayload",
 )
 
 
 class AppConfigNode(BaseResponseModel):
-    """Node model representing app configuration data."""
+    """Merged per-user AppConfig view (BEP-1052 §5).
+
+    `fragments` are ordered low → high merge priority (matching the
+    policy's `scope_sources`). `config` is the deep-merged result,
+    projected to `None` when every contributing fragment is empty
+    (§3 null projection).
+    """
+
+    user_id: UUID = Field(description="Target user's UUID.")
+    name: str = Field(description="Policy / config name.")
+    fragments: list[AppConfigFragmentNode] = Field(
+        description="Contributing fragments in merge order (low → high).",
+    )
+    config: dict[str, Any] | None = Field(
+        default=None,
+        description="Deep-merged configuration, or null when every fragment is empty.",
+    )
 
-    extra_config: dict[str, Any] = Field(description="Additional configuration data.")
 
+class GetUserAppConfigPayload(BaseResponseModel):
+    """Payload for reading a single merged AppConfig."""
 
-class DeleteDomainConfigPayload(BaseResponseModel):
-    """Payload for domain-level app config deletion mutation result."""
+    item: AppConfigNode | None = Field(
+        default=None,
+        description="Merged AppConfig, or null when no fragments exist for the user.",
+    )
 
-    deleted: bool = Field(description="Whether the deletion was successful.")
 
+class SearchAppConfigsPayload(BaseResponseModel):
+    """Payload for paginated merged-view AppConfig search."""
 
-class DeleteUserConfigPayload(BaseResponseModel):
-    """Payload for user-level app config deletion mutation result."""
+    items: list[AppConfigNode] = Field(description="AppConfigs matching the filter.")
+    total_count: int = Field(description="Total number of AppConfigs matching the filter.")
+    has_next_page: bool = Field(default=False, description="Whether there is a next page.")
+    has_previous_page: bool = Field(default=False, description="Whether there is a previous page.")
 
-    deleted: bool = Field(description="Whether the deletion was successful.")
 
+class BulkCreateMyAppConfigFragmentsPayload(BaseResponseModel):
+    """Payload for `bulkCreateMyAppConfigFragments`.
 
-class UpsertDomainConfigPayloadDTO(BaseResponseModel):
-    """Payload returned after upserting domain-level app configuration."""
+    Each successfully created row produces a recomputed merged
+    `AppConfigNode`; failures are collected per-item (BEP-1052 §3).
+    """
 
-    app_config: AppConfigNode = Field(description="The resulting app configuration")
+    created: list[AppConfigNode] = Field(
+        description="Recomputed merged AppConfig views for each created USER fragment.",
+    )
+    failed: list[AppConfigFragmentBulkError] = Field(description="Per-item failures.")
 
 
-class UpsertUserConfigPayloadDTO(BaseResponseModel):
-    """Payload returned after upserting user-level app configuration."""
+class BulkUpdateMyAppConfigFragmentsPayload(BaseResponseModel):
+    """Payload for `bulkUpdateMyAppConfigFragments`."""
 
-    app_config: AppConfigNode = Field(description="The resulting app configuration")
+    updated: list[AppConfigNode] = Field(
+        description="Recomputed merged AppConfig views for each updated USER fragment.",
+    )
+    failed: list[AppConfigFragmentBulkError] = Field(description="Per-item failures.")

src/ai/backend/common/dto/manager/v2/app_config/types.py

@@ -0,0 +1,23 @@
+"""
+Common types for AppConfig (merged view) DTO v2 (BEP-1052 §5).
+"""
+
+from __future__ import annotations
+
+from enum import StrEnum
+
+from ai.backend.common.dto.manager.v2.app_config_fragment.types import AppConfigScopeType
+from ai.backend.common.dto.manager.v2.common import OrderDirection
+
+__all__ = (
+    "AppConfigOrderField",
+    "AppConfigScopeType",
+    "OrderDirection",
+)
+
+
+class AppConfigOrderField(StrEnum):
+    """Fields available for ordering AppConfig merged-view results."""
+
+    USER_ID = "user_id"
+    NAME = "name"