enhance(backend): refine system account (#15530)

* wip

* wip

* wip

* Update SystemAccountService.ts

* Update 1740121393164-system-accounts.js

* Update DeleteAccountService.ts

* wip

* wip

* wip

* wip

* Update 1740121393164-system-accounts.js

* Update RepositoryModule.ts

* wip

* wip

* wip

* Update ApRendererService.ts

* wip

* wip

* Update SystemAccountService.ts

* fix tests

* fix tests

* fix tests

* fix tests

* fix tests

* fix tests

* add print logs

* ログが長すぎて出てないかもしれない

* fix migration

* refactor

* fix fed-tests

* Update RelayService.ts

* merge

* Update user.test.ts

* chore: emit log

* fix: tweak sleep duration

* fix: exit 1

* fix: wait for misskey processes to become healthy

* fix: longer sleep for user deletion

* fix: make sleep longer again

* デッドロック解消の試み

https://github.com/misskey-dev/misskey/issues/15005

* Revert "デッドロック解消の試み"

This reverts commit 266141f66f.

* wip

* Update SystemAccountService.ts

---------

Co-authored-by: おさむのひと <46447427+samunohito@users.noreply.github.com>
Co-authored-by: zyoshoka <107108195+zyoshoka@users.noreply.github.com>

packages/backend/src/core/entities/MetaEntityService.ts

@@ -11,8 +11,7 @@ import type { MiMeta } from '@/models/Meta.js';
 import type { AdsRepository } from '@/models/_.js';
 import { MAX_NOTE_TEXT_LENGTH } from '@/const.js';
 import { bindThis } from '@/decorators.js';
-import { UserEntityService } from '@/core/entities/UserEntityService.js';
-import { InstanceActorService } from '@/core/InstanceActorService.js';
+import { SystemAccountService } from '@/core/SystemAccountService.js';
 import type { Config } from '@/config.js';
 import { DI } from '@/di-symbols.js';
 import { DEFAULT_POLICIES } from '@/core/RoleService.js';
@@ -29,8 +28,7 @@ export class MetaEntityService {
 		@Inject(DI.adsRepository)
 		private adsRepository: AdsRepository,
 
-		private userEntityService: UserEntityService,
-		private instanceActorService: InstanceActorService,
+		private systemAccountService: SystemAccountService,
 	) { }
 
 	@bindThis
@@ -149,14 +147,14 @@ export class MetaEntityService {
 
 		const packed = await this.pack(instance);
 
-		const proxyAccount = instance.proxyAccountId ? await this.userEntityService.pack(instance.proxyAccountId).catch(() => null) : null;
+		const proxyAccount = await this.systemAccountService.fetch('proxy');
 
 		const packDetailed: Packed<'MetaDetailed'> = {
 			...packed,
 			cacheRemoteFiles: instance.cacheRemoteFiles,
 			cacheRemoteSensitiveFiles: instance.cacheRemoteSensitiveFiles,
-			requireSetup: !await this.instanceActorService.realLocalUsersPresent(),
-			proxyAccountName: proxyAccount ? proxyAccount.username : null,
+			requireSetup: this.meta.rootUserId == null,
+			proxyAccountName: proxyAccount.username,
 			features: {
 				localTimeline: instance.policies.ltlAvailable,
 				globalTimeline: instance.policies.gtlAvailable,