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/migration/1740129169650-system-accounts-2.js

@@ -0,0 +1,18 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+export class SystemAccounts21740129169650 {
+    name = 'SystemAccounts21740129169650'
+
+    async up(queryRunner) {
+        await queryRunner.query(`ALTER TABLE "meta" DROP CONSTRAINT "FK_ab1bc0c1e209daa77b8e8d212ad"`);
+        await queryRunner.query(`ALTER TABLE "meta" DROP COLUMN "proxyAccountId"`);
+    }
+
+    async down(queryRunner) {
+        await queryRunner.query(`ALTER TABLE "meta" ADD "proxyAccountId" character varying(32)`);
+        await queryRunner.query(`ALTER TABLE "meta" ADD CONSTRAINT "FK_ab1bc0c1e209daa77b8e8d212ad" FOREIGN KEY ("proxyAccountId") REFERENCES "user"("id") ON DELETE SET NULL ON UPDATE NO ACTION`);
+    }
+}