feat(lib): shelf sort/section pure helpers + formatSize extraction, table tests

frontend/src/components/ui.ts

@@ -1,5 +1,7 @@
 import type { Format } from "../api/types";
 
+export { formatSize } from "../lib/format"; // deprecated: phase-2 随阅读器清除
+
 export const btn =
   "inline-flex items-center gap-1.5 rounded-lg bg-white/[0.06] px-3 py-1.5 text-sm ring-1 ring-white/10 transition-colors hover:bg-white/[0.11] focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-amber-500 active:bg-white/[0.15] disabled:cursor-not-allowed disabled:opacity-50";
 export const btnPrimary =
@@ -27,12 +29,3 @@ export const FORMAT_BADGE: Record<Format, string> = {
 export function formatBadge(fmt: Format, extra = ""): string {
   return `rounded px-1.5 py-0.5 text-[10px] font-semibold uppercase tracking-wide ring-1 ${FORMAT_BADGE[fmt]} ${extra}`;
 }
-
-export function formatSize(bytes: number): string {
-  if (bytes <= 0) return "";
-  const units = ["B", "KB", "MB", "GB"];
-  let i = 0;
-  let n = bytes;
-  for (; n >= 1024 && i < units.length - 1; i++) n /= 1024;
-  return `${n >= 10 || i === 0 ? Math.round(n) : n.toFixed(1)} ${units[i]}`;
-}