feat: license violation protection (#13285)

* spec(frontend): aboutページにリポジトリ・フィードバックのURLを表示させる

Cherry-picked from MisskeyIO#441
Cherry-picked from MisskeyIO#438

* feat: license violation protection

* build: fix typo

* build: fix typo

* fix: farewell to the static type land

* fix: key typo

* fix: import typo

* fix: properly interpret `prominently`

* docs: add disclaimer

* docs: update CHANGELOG

* chore: add gap

---------

Co-authored-by: まっちゃとーにゅ <17376330+u1-liquid@users.noreply.github.com>
Co-authored-by: syuilo <4439005+syuilo@users.noreply.github.com>

packages/backend/migration/1707808106310-MakeRepositoryUrlNullable.js

@@ -0,0 +1,16 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+export class MakeRepositoryUrlNullable1707808106310 {
+    name = 'MakeRepositoryUrlNullable1707808106310'
+
+    async up(queryRunner) {
+        await queryRunner.query(`ALTER TABLE "meta" ALTER COLUMN "repositoryUrl" DROP NOT NULL`);
+    }
+
+    async down(queryRunner) {
+        await queryRunner.query(`ALTER TABLE "meta" ALTER COLUMN "repositoryUrl" SET NOT NULL`);
+    }
+}