fix(keys): epic-end review round 3 — the part-way clip count shows, busy buttons keep focus, cards say their names

Targeted round over 3cd0c525's fix surfaces: 14 raised, 14 fixed.

- VideoEditor: the "only X of Y clips" toast went silent exactly on the job-cap/quota refusal it was
  written for (req had already reported the error); it now always shows. The cut list holds still while
  Create queues, and a retry continues the "(i/N)" series.
- ChannelPage: Subscribe/Unsubscribe use Button `loading`, "Load more" and ChannelDiscovery's Subscribe
  block the click with aria-disabled instead of native disabled; busy Block/Hide no longer light up on
  hover.
- listNav: an item can name itself (`navItemAttrs(i, name)`) — Plex posters, seasons, episodes, message
  rows and download rows pass their title; focus on a toast's Undo keeps the removed card's slot.
- AnchoredPopover: the hand-back only for focus-managed surfaces (a hover card no longer pulls focus
  back); the dead panel-ref check is gone.
- AccountPanel: no confirmation mail offered to the demo account; send_failed copy no longer blames
  the message for an unreachable server. Pager comment points at scrollParent.

frontend/src/components/VideoEditor.partial.dom.test.tsx

@@ -1,11 +1,12 @@
 // @vitest-environment jsdom
 //
-// A split export that fails part-way (deep-review E11 round 2). Every clip is its own job, committed as
-// it goes, so a failure at clip 2 of 2 (the job cap) left clip 1 queued while the editor reported a
-// plain failure and kept both selected — and trying again queued clip 1 a second time. It now says how
-// many made it and deselects them, so another try adds only the rest.
+// A split export that fails part-way (deep-review E11 rounds 2 and 3). Every clip is its own job,
+// committed as it goes, so a failure at clip 2 of 2 (the job cap) left clip 1 queued while the editor
+// reported a plain failure and kept both selected — and trying again queued clip 1 a second time. It
+// now says how many made it (also when `req` has already shown the refusal in its dialog), deselects
+// them, holds the cut list still while it queues, and a retry goes on with the same "(i/N)" series.
 import { describe, it, expect, vi, beforeAll, afterEach } from "vitest";
-import { render, screen, fireEvent, waitFor, cleanup } from "@testing-library/react";
+import { render, screen, fireEvent, waitFor, cleanup, act } from "@testing-library/react";
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 
 vi.mock("react-i18next", async (importOriginal) => ({
@@ -20,6 +21,7 @@ vi.mock("../lib/notifications", async (importOriginal) => ({
 
 import VideoEditor from "./VideoEditor";
 import { api, HttpError, type DownloadJob } from "../lib/api";
+import { markReported } from "../lib/api/core";
 
 beforeAll(() => {
   class Stub {
@@ -48,10 +50,16 @@ const job = {
 describe("VideoEditor — a split export that fails part-way", () => {
   it("says how many clips made it, and a retry queues only the rest", async () => {
     vi.spyOn(api, "downloadStoryboard").mockResolvedValue({ available: false } as never);
+    let refuse: (e: unknown) => void = () => {};
     const enqueue = vi
       .spyOn(api, "enqueueEdit")
       .mockResolvedValueOnce({} as never)
-      .mockRejectedValueOnce(new HttpError(422, "errors.generic", { code: "quota" }))
+      .mockImplementationOnce(
+        () =>
+          new Promise((_, reject) => {
+            refuse = reject;
+          }) as never,
+      )
       .mockResolvedValue({} as never);
     render(
       <QueryClientProvider client={new QueryClient()}>
@@ -59,23 +67,37 @@ describe("VideoEditor — a split export that fails part-way", () => {
       </QueryClientProvider>,
     );
 
-    // Split at 50 s: the playhead is where the video element says it is.
+    // The playhead is where the video element says it is.
     const video = document.querySelector("video")!;
-    Object.defineProperty(video, "currentTime", { value: 50, configurable: true, writable: true });
-    fireEvent.timeUpdate(video);
+    const playhead = (s: number) => {
+      Object.defineProperty(video, "currentTime", { value: s, configurable: true, writable: true });
+      fireEvent.timeUpdate(video);
+    };
+    playhead(50);
     fireEvent.click(screen.getByText("editor.splitHere"));
 
     fireEvent.click(screen.getByText("editor.createN"));
+    await waitFor(() => expect(enqueue).toHaveBeenCalledTimes(2));
+    // While the clips are queued the cut list holds still: a split now would be a range never queued.
+    playhead(75);
+    fireEvent.click(screen.getByText("editor.splitHere"));
+
+    // The job cap, as `req` delivers it: already shown in the error dialog, and marked reported.
+    const refused = new HttpError(422, "errors.generic", { code: "quota" });
+    markReported(refused);
+    await act(async () => refuse(refused));
     await waitFor(() =>
       expect(notify).toHaveBeenCalledWith(
         expect.objectContaining({ level: "error", title: "editor.partlyCreated" }),
       ),
     );
-    expect(enqueue).toHaveBeenCalledTimes(2);
+    expect(enqueue.mock.calls[0]![0].display_name).toBe("Talk (1/2)");
 
-    // The queued first clip is deselected: one clip left to create, and only it is sent again.
+    // The queued first clip is deselected: one clip left to create, and only it is sent again — as
+    // the second of the same two.
     fireEvent.click(screen.getByText("editor.create"));
     await waitFor(() => expect(enqueue).toHaveBeenCalledTimes(3));
     expect(enqueue.mock.calls[2]![0].edit_spec.trim).toEqual({ start_s: 50, end_s: 100 });
+    expect(enqueue.mock.calls[2]![0].display_name).toBe("Talk (2/2)");
   });
 });