feat: persistent memories (#8330)

* feat: persistent memories

* refactor: use new add/remove asset utility

server/test/fixtures/memory.stub.ts

@@ -0,0 +1,30 @@
+import { MemoryEntity, MemoryType } from 'src/entities/memory.entity';
+import { assetStub } from 'test/fixtures/asset.stub';
+import { userStub } from 'test/fixtures/user.stub';
+
+export const memoryStub = {
+  empty: <MemoryEntity>{
+    id: 'memoryEmpty',
+    createdAt: new Date(),
+    updatedAt: new Date(),
+    memoryAt: new Date(2024),
+    ownerId: userStub.admin.id,
+    owner: userStub.admin,
+    type: MemoryType.ON_THIS_DAY,
+    data: { year: 2024 },
+    isSaved: false,
+    assets: [],
+  },
+  memory1: <MemoryEntity>{
+    id: 'memory1',
+    createdAt: new Date(),
+    updatedAt: new Date(),
+    memoryAt: new Date(2024),
+    ownerId: userStub.admin.id,
+    owner: userStub.admin,
+    type: MemoryType.ON_THIS_DAY,
+    data: { year: 2024 },
+    isSaved: false,
+    assets: [assetStub.image1],
+  },
+};