fix(plex): a collection kept after a failed refresh holds its seed title

When Plex made the collection and only the read after it failed, the kept row had no members: the
title showed unticked in the collection it had just been added to, the collection empty, and the
name stayed in the field for a retry that could only be refused as taken. The seed's row now names
the collection (child_count 1), and the panel clears the field on that refusal as on success. Also
held: the panel's lines sit beside its list, and a keyboard Retry lands on the first row.

frontend/src/components/PlexMenu.dom.test.tsx

@@ -8,7 +8,7 @@ import { cleanup, fireEvent, render, screen } from "@testing-library/react";
 import { FloatingTree } from "@floating-ui/react";
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 
-import { api, type PlexCard, type PlexCollection } from "../lib/api";
+import { api, HttpError, type PlexCard, type PlexCollection } from "../lib/api";
 import { qk } from "../lib/queryKeys";
 
 vi.mock("react-i18next", async (importOriginal) => {
@@ -361,9 +361,35 @@ describe("a Plex title's menu — Add to collection", () => {
     const alert = await screen.findByRole("alert", { hidden: true });
     expect(alert.textContent).toContain("plex.collectionAdd.loadFailed");
     expect(screen.queryByText("plex.collectionAdd.none")).toBeNull();
+    // A menu owns its items only: the line about the list sits beside it, not in it.
+    expect(document.querySelector("[role=menu]")).not.toBeNull();
+    expect(alert.closest("[role=menu]")).toBeNull();
     list.mockResolvedValue({ collections: [coll("cB", "Beta", false)] });
-    fireEvent.click(await screen.findByText("common.retry"));
-    await checkRow("Beta");
+    // Retry from the keyboard: the focused button goes as the list loads, and focus must not be left
+    // on <body> with the menu open — it lands on the first row that came back.
+    const retry = (await screen.findByText("common.retry")).closest("button")!;
+    retry.focus();
+    fireEvent.click(retry);
+    const beta = await checkRow("Beta");
+    await vi.waitFor(() => expect(document.activeElement).toBe(beta));
+  });
+
+  it("clears the name when Plex made the collection and only the read after it failed", async () => {
+    vi.spyOn(api, "plexCollectionsFor").mockResolvedValue({ collections: [] });
+    const create = vi
+      .spyOn(api, "plexCreateCollection")
+      .mockRejectedValue(
+        new HttpError(422, "pending", { code: "refused", reason: "collection_pending_sync" }),
+      );
+    setup(card({}), {}, { admin: true });
+    rightClick();
+    fireEvent.click(item("plex.collectionAdd.row"));
+    const name = await screen.findByLabelText<HTMLInputElement>("plex.collection.namePlaceholder");
+    fireEvent.change(name, { target: { value: "Noir" } });
+    fireEvent.keyDown(name, { key: "Enter" });
+    await vi.waitFor(() => expect(create).toHaveBeenCalledTimes(1));
+    // It exists now: a second Enter on the kept name could only be refused as taken.
+    await vi.waitFor(() => expect(name.value).toBe(""));
   });
 
   it("steps from the name field into the rows with the arrows — rows that arrived after it opened", async () => {