fix(ui): a card's Play clears its hover row at a large text size; Downloads links and the player description

At text size 1.3 a 242px feed thumbnail put the 63px Play 13px into the
hover row (the Play grows with the root font, the picture's height does
not). A picture narrower than 14rem centres the Play and the resume pair
above the row; the picture box is a size container for it.

The Downloads title and channel links were 21px tall inline boxes; they
stand on a 24px line now (B1). The player's description says a failed
load, with a retry, instead of 'No description' (both the side panel
and the popover).

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

@@ -9,7 +9,7 @@
 // test that leaves `window.YT` unset). Each item the modal plays constructs a new YT.Player, and the
 // fake records what it was asked for — that is how these tests see where playback starts.
 import { describe, it, expect, vi, afterEach, beforeAll, beforeEach } from "vitest";
-import { render, screen, fireEvent, waitFor, cleanup, act } from "@testing-library/react";
+import { render, screen, fireEvent, waitFor, cleanup, act, within } from "@testing-library/react";
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 import type { ReactNode } from "react";
 
@@ -542,6 +542,27 @@ describe("PlayerModal — the side panel on a wide window", () => {
     expect(spin(document.querySelector(".player-stage")!, 100)).toBe(true); // over the video
   });
 
+  // E31 S5: a failed load read "No description." in the always-open panel — an error drawn as empty.
+  it("says the description failed to load, with a retry, instead of 'No description'", async () => {
+    wideWindow(true);
+    const detail = vi
+      .spyOn(api, "videoDetail")
+      .mockRejectedValueOnce(new Error("boom"))
+      .mockResolvedValue({ description: "A long description" } as Awaited<
+        ReturnType<typeof api.videoDetail>
+      >);
+    const A = vid("A", 0);
+    renderModal(
+      <PlayerModal video={A} queue={[A]} startIndex={0} onClose={() => {}} onState={() => {}} />,
+    );
+    const panel = screen.getByTestId("player-description");
+    expect(await within(panel).findByText("player.descriptionFailed")).toBeTruthy();
+    expect(within(panel).queryByText("player.noDescription")).toBeNull();
+    fireEvent.click(within(panel).getByRole("button", { name: "common.retry" }));
+    expect(await within(panel).findByText("A long description")).toBeTruthy();
+    expect(detail).toHaveBeenCalledTimes(2);
+  });
+
   it("keeps the details under the video below 1280 px", () => {
     wideWindow(false);
     vi.spyOn(api, "videoDetail").mockReturnValue(new Promise(() => {}));