feat(admin): reorganize housekeeping and strengthen shared workflows

src/lib/furni/import-job-retry.ts

@@ -0,0 +1,10 @@
+import type { ImportJob } from "./import-job";
+/** Never requeue an active job or furniture already imported successfully. */
+export function retryableJobItems(job: ImportJob): ImportJob["items"] {
+	if (job.state === "running" || job.state === "queued") return [];
+	return job.items.filter(
+		(item) =>
+			item.state === "failed" ||
+			(job.state === "interrupted" && item.state !== "done"),
+	);
+}