feat: complete TASK-WP0-05 storage capacity

apps/worker/src/storage-maintenance.ts

@@ -0,0 +1,10 @@
+export interface StorageMaintenanceTarget {
+  processCleanupQueue(): Promise<{ completed: number; failed: number }>;
+  reconcileStartup(): Promise<{ orphaned: number; released_reservations: number }>;
+}
+
+export async function runStorageMaintenance(target: StorageMaintenanceTarget) {
+  const reconciliation = await target.reconcileStartup();
+  const cleanup = await target.processCleanupQueue();
+  return { cleanup, reconciliation };
+}