feat(FN-3891): document memory backup settings in settings reference

Documents the memory backup feature in the settings reference and adds a changeset to prepare for publishing.

Fusion-Task-Id: FN-3891

packages/core/src/index.ts

@@ -241,6 +241,16 @@ export {
   BACKUP_SCHEDULE_NAME,
 } from "./backup.js";
 export type { BackupInfo, BackupOptions } from "./backup.js";
+export {
+  MemoryBackupManager,
+  createMemoryBackupManager,
+  runMemoryBackupCommand,
+  validateMemoryBackupSchedule,
+  MEMORY_BACKUP_SCHEDULE_NAME,
+  syncMemoryBackupAutomation,
+  syncMemoryBackupRoutine,
+} from "./memory-backup.js";
+export type { MemoryBackupInfo, MemoryBackupOptions } from "./memory-backup.js";
 export {
   exportSettings,
   importSettings,