feat(admin): archived-items page with purge dates, restore, and purge

Admins need to see what the archive lifecycle is holding: a dedicated
/admin/archived page listing every hidden item (archived or still in
the missing grace window) with library, file path, status, and - when
retention is enabled - the exact date it will be permanently deleted
(archived_at + ARCHIVE_RETENTION_DAYS).

Per row: Restore (POST /api/media-items/:id/unarchive, clears the
archive state so it reappears; if the file is still gone the next scan
hides it again) and Delete (existing DELETE endpoint for single-row
purge with its reading history). Purge All Archived reuses the existing
bulk button. The library admin banner links to the page and keeps its
purge button; row actions use data attributes with delegated listeners
in admin.ts since this templ version has no JSFunctionCall helper.

Verified live: page 200 with purge dates shown, unarchive returned 204
and reset the row, per-item delete and bulk purge ({purged:1}) both
removed their rows with no leftovers.

web/src/admin.ts

@@ -289,6 +289,67 @@ async function purgeArchivedItems(): Promise<void> {
 
 (window as any).purgeArchivedItems = purgeArchivedItems;
 
+// Restore a hidden/archived item to library visibility without waiting for
+// its file to return (POST /api/media-items/:id/unarchive). If the file is
+// still gone the next scan hides it again.
+async function unarchiveItem(id: string): Promise<void> {
+  const token = localStorage.getItem("token");
+  if (!token) return;
+  try {
+    const resp = await fetch(`/api/media-items/${id}/unarchive`, {
+      method: "POST",
+      headers: { Authorization: `Bearer ${token}` },
+    });
+    if (!resp.ok) {
+      const err = await resp.json().catch(() => ({}));
+      throw new Error(err.error || "Failed to restore item");
+    }
+    showToast("Item restored to libraries", "success");
+    setTimeout(() => window.location.reload(), 500);
+  } catch (e) {
+    showToast(e instanceof Error ? e.message : "Failed to restore item", "error");
+  }
+}
+
+// Permanently delete one archived item and its reading history
+// (DELETE /api/media-items/:id).
+async function deleteArchivedItem(id: string): Promise<void> {
+  const token = localStorage.getItem("token");
+  if (!token) return;
+  if (
+    !window.confirm(
+      "Permanently delete this item? Its reading progress, notes, and highlights will be lost.",
+    )
+  ) {
+    return;
+  }
+  try {
+    const resp = await fetch(`/api/media-items/${id}`, {
+      method: "DELETE",
+      headers: { Authorization: `Bearer ${token}` },
+    });
+    if (!resp.ok) {
+      const err = await resp.json().catch(() => ({}));
+      throw new Error(err.error || "Failed to delete item");
+    }
+    showToast("Item deleted", "success");
+    setTimeout(() => window.location.reload(), 500);
+  } catch (e) {
+    showToast(e instanceof Error ? e.message : "Failed to delete item", "error");
+  }
+}
+
+// The archived-items page renders per-row buttons with data attributes
+// (escaping-safe); bind them here. Module scripts run after DOM parse.
+document.querySelectorAll<HTMLElement>("[data-unarchive]").forEach((el) => {
+  el.addEventListener("click", () => unarchiveItem(el.dataset.unarchive || ""));
+});
+document.querySelectorAll<HTMLElement>("[data-delete-archived]").forEach((el) => {
+  el.addEventListener("click", () =>
+    deleteArchivedItem(el.dataset.deleteArchived || ""),
+  );
+});
+
 export {
   hideScanProgress,
   loadWatchStatus,