feat(web): DataTable groupBy with collapsible counted group headers

Groups keep first-seen order (or a custom order), headers show counts and
toggle with aria-expanded; collapsed groups persist per storageKey in
localStorage (read after mount, failures ignored). The trash list groups by
registered directory when items span more than one.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

apps/web/app/components/console/data-table-groups.ts

@@ -0,0 +1,58 @@
+// DataTable groupBy 的纯逻辑:按键分组(保持首次出现顺序或自定义顺序)与展开态持久化。
+
+export type RowGroup<T> = { key: string; rows: T[] };
+
+/** 按 key 分组;缺省按首次出现顺序,给 order 时按 order 排组(组内保持原顺序) */
+export function groupRows<T>(
+  rows: readonly T[],
+  keyOf: (row: T) => string,
+  order?: (a: string, b: string) => number,
+): RowGroup<T>[] {
+  const map = new Map<string, T[]>();
+  for (const r of rows) {
+    const k = keyOf(r);
+    const list = map.get(k);
+    if (list) list.push(r);
+    else map.set(k, [r]);
+  }
+  const groups = [...map].map(([key, rs]) => ({ key, rows: rs }));
+  return order ? groups.sort((a, b) => order(a.key, b.key)) : groups;
+}
+
+const PREFIX = "umt.table-groups:";
+type Store = Pick<Storage, "getItem" | "setItem">;
+const defaultStore = (): Store | undefined => globalThis.localStorage;
+
+/** 读折叠的组(localStorage 不可用或内容损坏时为 null,由调用方取缺省) */
+export function readCollapsed(storageKey: string | undefined, store = defaultStore): Set<string> | null {
+  if (!storageKey) return null;
+  try {
+    const raw = store()?.getItem(PREFIX + storageKey);
+    if (!raw) return null;
+    const v = JSON.parse(raw) as unknown;
+    return Array.isArray(v) ? new Set(v.filter((x): x is string => typeof x === "string")) : null;
+  } catch {
+    return null;
+  }
+}
+
+export function writeCollapsed(
+  storageKey: string | undefined,
+  collapsed: ReadonlySet<string>,
+  store = defaultStore,
+): void {
+  if (!storageKey) return;
+  try {
+    store()?.setItem(PREFIX + storageKey, JSON.stringify([...collapsed]));
+  } catch {
+    // 私密窗口 / 配额满:只是不记住
+  }
+}
+
+/** 切换一个组的折叠态,返回新集合 */
+export function toggleCollapsed(collapsed: ReadonlySet<string>, key: string): Set<string> {
+  const next = new Set(collapsed);
+  if (next.has(key)) next.delete(key);
+  else next.add(key);
+  return next;
+}