feat: add snjs package

packages/snjs/lib/Migrations/Versions/2_0_15.ts

@@ -0,0 +1,21 @@
+import { ApplicationStage } from '@standardnotes/services'
+import { Migration } from '@Lib/Migrations/Migration'
+
+export class Migration2_0_15 extends Migration {
+  static override version(): string {
+    return '2.0.15'
+  }
+
+  protected registerStageHandlers(): void {
+    this.registerStageHandler(ApplicationStage.LoadedDatabase_12, async () => {
+      await this.createNewDefaultItemsKeyIfNecessary()
+      this.markDone()
+    })
+  }
+
+  private async createNewDefaultItemsKeyIfNecessary() {
+    if (this.services.protocolService.needsNewRootKeyBasedItemsKey()) {
+      await this.services.protocolService.createNewDefaultItemsKey()
+    }
+  }
+}