refactor(BA-5837): propagate my_bulk_* rename + BEP cleanup to ValkeyCache surface

Carry the stack-wide `bulk_create_my` / `bulk_update_my` →
`my_bulk_create` / `my_bulk_update` rename through the cache_source
module added by this PR, plus the GQL / adapter / DTO touchpoints that
the rebase resolved with `-X theirs` (which kept stale identifiers).

Also strip the residual `BEP-1052 §X` references from the cache_source
docstring and the merged-view repository docstring. Only the news
fragments retain the BEP wording.

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

Author: jopemachine

src/ai/backend/manager/repositories/app_config_fragment/cache_source/cache_source.py

@@ -2,7 +2,7 @@
 
 The hot path is `AppConfigFragmentRepository.app_config(user_id, name)`,
 the per-`(user, name)` deep-merge of every contributing fragment in
-the policy's `scope_sources` chain (BEP-1052 §5). Each merged value
+the policy's `scope_sources` chain. Each merged value
 gets cached under `app_config:merged:{user_id}:{name}` with a TTL,
 and is invalidated whenever a contributing fragment changes.
 

src/ai/backend/manager/repositories/app_config_fragment/repository.py

@@ -50,7 +50,7 @@ class AppConfigFragmentRepository:
     """Read-side repository for AppConfigFragment.
 
     Scope-bound reads on raw fragments plus the per-user merged
-    `AppConfig` view (BEP-1052 §5). Mutations and admin cross-scope
+    `AppConfig` view. Mutations and admin cross-scope
     reads live on `AppConfigFragmentAdminRepository`. Retry + metric
     policies are applied at the DB-source layer; the merged-view read
     path is fronted by a Valkey cache so repeated WebUI bootstrap