refactor(infra): directory structure (#4615)

packages/frontend/electron/src/helper/db/subjects.ts

@@ -0,0 +1,9 @@
+import { Subject } from 'rxjs';
+
+export const dbSubjects = {
+  externalUpdate: new Subject<{
+    workspaceId: string;
+    update: Uint8Array;
+    docId?: string;
+  }>(),
+};