fix(player): related marks survive, Restart restarts, and refused pages offer nothing to click

- Every state and Watch-later write goes through features/video/videoWrites,
  which marks the never-refetched lists (related lists, live searches) once
  the server has it; a contract test holds it. The Notification Center's
  undo, the feed's reset and the Watch-later toggles skipped it before.
- Confirmed marks are also kept apart (qk.videoMarks) and laid over the
  related rows: a Show more page landing later rebuilt them from the pages
  it read when it started, and dropped a mark made meanwhile.
- Restart on a related video starts at 0 (the session's stored position
  won before), and on the one already playing it seeks.
- The watched toggle remembers each video's mark: Back showed the opened
  video's launch-time state after a related one was marked.
- The help sheet leaves out the player's keys while a layer above it has
  them waiting.
- After a refusal a retry cannot answer, neither Show more (related) nor
  Load more (live search) is offered; a failed live-search page keeps the
  results already read and says why under them.
- The related cap message counts requests, as the cap does.

frontend/src/components/ui/KeyboardHelp.dom.test.tsx

@@ -9,6 +9,7 @@ import KeyboardHelp from "./KeyboardHelp";
 import { useContextMenu } from "./useContextMenu";
 import {
   closeKeyboardHelp,
+  setScopeCoveredProbe,
   useGlobalKeymap,
   useHelpConditions,
   useKeyScope,
@@ -179,6 +180,33 @@ describe("KeyboardHelp", () => {
     expect(descriptions()).not.toContain("keys.contextMenu");
   });
 
+  // The YouTube player's keys wait while a layer sits above it (its related drawer, a dialog): a
+  // sheet opened there leaves them out, and one opened over the player itself lists them.
+  it("leaves out a surface's keys while a layer above it has them waiting", () => {
+    let covered = true;
+    setScopeCoveredProbe("ytPlayer", () => covered);
+    try {
+      render(
+        <Host>
+          <Surface scope="ytPlayer" />
+        </Host>,
+      );
+      const id = pushLayer();
+      pressH();
+      removeLayer(id);
+      expect(descriptions()).not.toContain("keys.playPause");
+      expect(descriptions()).toContain("keys.help");
+      act(() => closeKeyboardHelp());
+      covered = false;
+      pressH();
+      expect(descriptions()).toContain("keys.playPause");
+    } catch (e) {
+      setScopeCoveredProbe("ytPlayer", null);
+      throw e;
+    }
+    setScopeCoveredProbe("ytPlayer", null);
+  });
+
   // Two live context menus (the Playlists page mounts one, its rail another) must not double the row.
   it("lists the context-menu chords once however many surfaces register", () => {
     function WithMenu() {

frontend/src/components/ui/KeyboardHelp.tsx

@@ -10,6 +10,7 @@ import {
   useHelpConditionValues,
   useKeyboardHelpOpen,
   useKeyboardHelpOverLayer,
+  useKeyboardHelpCovered,
   useNavigablePages,
 } from "../../lib/keymap";
 
@@ -33,6 +34,7 @@ export default function KeyboardHelp() {
   const scopes = useActiveScopes();
   const conditions = useHelpConditionValues();
   const overLayer = useKeyboardHelpOverLayer();
+  const covered = useKeyboardHelpCovered();
   const pages = useNavigablePages();
 
   if (!open) return null;
@@ -47,7 +49,10 @@ export default function KeyboardHelp() {
   const inLayer = (s: (typeof scopes)[number]) =>
     (!isPageLevelScope(s) && s !== "contextMenu") ||
     (overLayer === "layerWithList" && (s === "list" || s === "contextMenu"));
-  const live = overLayer === "page" ? scopes : scopes.filter(inLayer);
+  // A surface under a layer of its own (the player under its related drawer) waits: not listed.
+  const live = (overLayer === "page" ? scopes : scopes.filter(inLayer)).filter(
+    (s) => !covered.has(s),
+  );
   const lines = helpLines(live, pages).filter((l) => !l.when || !!conditions[l.when]);
   const words = { Space: t("keys.cap.space"), ContextMenu: t("keys.cap.menu") };
   return (

frontend/src/features/player/PlayerModal.dom.test.tsx

@@ -35,6 +35,8 @@ vi.mock("../downloads/DownloadButton", () => ({
 }));
 
 import PlayerModal from "./PlayerModal";
+import KeyboardHelp from "../../components/ui/KeyboardHelp";
+import { closeKeyboardHelp, toggleKeyboardHelp } from "../../lib/keymap";
 import { ConfirmProvider } from "../../components/ui/ConfirmProvider";
 import { useConfirm } from "../../components/ui/confirmContext";
 import { api, type Me, type Video } from "../../lib/api";
@@ -837,6 +839,7 @@ describe("PlayerModal — the side panel on a wide window", () => {
   const playRel2 = async (
     onState: (id: string, status: string, v?: Video) => void,
     queue?: Video[],
+    opts: { onRemoveFromList?: (v: Video) => Promise<boolean>; before?: () => void } = {},
   ) => {
     wideWindow(true);
     vi.spyOn(api, "videoDetail").mockReturnValue(new Promise(() => {}));
@@ -853,9 +856,11 @@ describe("PlayerModal — the side panel on a wide window", () => {
         startIndex={0}
         onClose={() => {}}
         onState={onState}
+        onRemoveFromList={opts.onRemoveFromList}
       />,
     );
     act(() => playerEvents.onReady?.());
+    opts.before?.();
     fireEvent.click(screen.getByRole("tab", { name: "player.related.title" }));
     fireEvent.click(titleOf(await screen.findAllByRole("link", { name: "Video rel2" })));
     await waitFor(() => expect(lastStart()?.videoId).toBe("rel2"));
@@ -898,6 +903,77 @@ describe("PlayerModal — the side panel on a wide window", () => {
     expect(lastStart()?.videoId).toBe("rel2");
   });
 
+  // Restart is where the user asked to start: a position this session stored for the video (which a
+  // plain pick resumes from) must not win over it.
+  it("wide: Restart on a related video played this session starts it at 0", async () => {
+    vi.spyOn(api, "saveProgress").mockImplementation(async (id: string) => ({
+      video_id: id,
+      position_seconds: id === "rel2" ? 500 : 77,
+    }));
+    clock.current = 77;
+    await playRel2(() => {});
+    clock.current = 500;
+    fireEvent.click(screen.getByRole("button", { name: "player.back" }));
+    await waitFor(() => expect(lastStart()?.videoId).toBe("A"));
+    await settle();
+    const list = screen.getByTestId("player-related");
+    const row = within(list)
+      .getAllByRole("link", { name: "Video rel2" })[0]!
+      .closest("[data-nav-index]")!;
+    fireEvent.click(within(row as HTMLElement).getAllByTitle("card.restartTitle")[0]!);
+    await waitFor(() => expect(lastStart()?.videoId).toBe("rel2"));
+    // A start of 0 is no `start` at all (the player starts at the top).
+    expect(lastStart()?.start ?? 0).toBe(0);
+  });
+
+  // Its row stays in the list while it plays; a new player for the same video is never built (one
+  // per video), so Restart there is a seek.
+  it("wide: Restart on the related video already playing seeks it to 0", async () => {
+    await playRel2(() => {});
+    const before = started.length;
+    const list = screen.getByTestId("player-related");
+    const row = within(list)
+      .getAllByRole("link", { name: "Video rel2" })[0]!
+      .closest("[data-nav-index]")!;
+    fireEvent.click(within(row as HTMLElement).getAllByTitle("card.restartTitle")[0]!);
+    expect(seeks).toContain(0);
+    expect(started.length).toBe(before);
+  });
+
+  // The toggle remembers each video's mark: a related one's did not overwrite the opened one's.
+  it("wide: Back shows the opened video's own mark, not the one it was opened with", async () => {
+    const onState = vi.fn();
+    await playRel2(onState, undefined, {
+      before: () => fireEvent.click(screen.getAllByTitle("player.markWatched")[0]!),
+    });
+    fireEvent.click(screen.getAllByTitle("player.markWatched")[0]!); // rel2's
+    expect(onState.mock.calls.map((c) => c.slice(0, 2))).toEqual([
+      ["A", "watched"],
+      ["rel2", "watched"],
+    ]);
+    fireEvent.click(screen.getByRole("button", { name: "player.back" }));
+    await waitFor(() => expect(lastStart()?.videoId).toBe("A"));
+    expect(screen.getAllByTitle("player.watchedUnmark").length).toBeGreaterThan(0);
+    expect(screen.queryAllByTitle("player.markWatched")).toHaveLength(0);
+  });
+
+  it("wide: a queue step leaves the related video for the queue's next item", async () => {
+    await playRel2(() => {}, [vid("A", 40), vid("B", 0)]);
+    next();
+    await waitFor(() => expect(lastStart()?.videoId).toBe("B"));
+    expect(screen.getByRole("heading", { name: "Video B" })).toBeTruthy();
+    expect(screen.queryByRole("button", { name: "player.back" })).toBeNull();
+  });
+
+  // Removing from the list removes the queue's item — not the related video on screen.
+  it("wide: offers no removal from the list while a related video plays", async () => {
+    await playRel2(() => {}, undefined, { onRemoveFromList: async () => true });
+    expect(screen.queryByRole("button", { name: /playlists\.removeItemOf/ })).toBeNull();
+    fireEvent.click(screen.getByRole("button", { name: "player.back" }));
+    await waitFor(() => expect(lastStart()?.videoId).toBe("A"));
+    expect(trash("A")).toBeTruthy();
+  });
+
   it("leaves the related videos out when the instance turned them off", () => {
     me = { related_enabled: false } as Me;
     vi.spyOn(api, "videoDetail").mockReturnValue(new Promise(() => {}));
@@ -1037,6 +1113,23 @@ describe("PlayerModal — the side panel on a wide window", () => {
     expect(seeks).toEqual([]);
   });
 
+  // So the help sheet opened over the drawer does not promise them; over the player itself, it does.
+  it("stacked: the help sheet over the drawer leaves the video's keys out", async () => {
+    wideWindow(false);
+    const { drawer } = await openDrawer();
+    render(<KeyboardHelp />);
+    act(() => toggleKeyboardHelp());
+    expect(screen.queryByText("keys.playPause")).toBeNull();
+    act(() => closeKeyboardHelp());
+    fireEvent.click(within(drawer).getByRole("button", { name: "common.close" }));
+    await waitFor(() =>
+      expect(screen.queryByRole("dialog", { name: "player.related.title" })).toBeNull(),
+    );
+    act(() => toggleKeyboardHelp());
+    expect(screen.getByText("keys.playPause")).toBeTruthy();
+    act(() => closeKeyboardHelp());
+  });
+
   it("stacked: the window regaining focus leaves it in the drawer", async () => {
     wideWindow(false);
     const { drawer } = await openDrawer();

frontend/src/features/player/PlayerModal.tsx

@@ -65,7 +65,7 @@ import {
   relativeTime,
 } from "../../lib/format";
 import { canFullscreenElements, fullscreenElement } from "../../lib/fullscreen";
-import { dispatch, isActivationTarget, useKeyScope } from "../../lib/keymap";
+import { dispatch, isActivationTarget, setScopeCoveredProbe, useKeyScope } from "../../lib/keymap";
 import { useBackToClose } from "../../lib/history";
 import ChannelNameLink from "../video/ChannelNameLink";
 import Toaster from "../../components/ui/Toaster";
@@ -248,14 +248,18 @@ export default function PlayerModal({
   // controls show — while the queue stays where it was, and Back returns to the opened item. It is
   // the SUBJECT of the player from here down; `active` stays the queue's item, which the related
   // list, the counter and prev/next belong to. A queue step leaves it.
-  const [related, setRelated] = useState<{ video: Video; startAt: number } | null>(null);
+  // `startAt` null resumes it where it was left (this session's stored position first); a number is
+  // where the user asked it to start — Restart's 0 — and beats that position.
+  const [related, setRelated] = useState<{ video: Video; startAt: number | null } | null>(null);
   const [relatedOf, setRelatedOf] = useState(active.id);
   if (relatedOf !== active.id) {
     setRelatedOf(active.id);
     setRelated(null);
   }
   const subject = related?.video ?? active;
-  const subjectResume = related ? related.startAt : resumeAt;
+  const subjectResume = related
+    ? (related.startAt ?? related.video.position_seconds ?? 0)
+    : resumeAt;
   const mountRef = useRef<HTMLDivElement | null>(null);
   const playerRef = useRef<YTPlayer | null>(null);
   // Keyboard/wheel controls. We keep focus on the modal card (not the cross-origin player
@@ -547,14 +551,11 @@ export default function PlayerModal({
   // item's, so the toggle falls back to `subject.status` and no ordering has to be argued about.
   // Unkeyed it landed last and painted the NEXT video as watched; a corrective click then sent
   // onState(next, "new") for an item that was already new.
-  const [status, setStatus] = useState<{ id: string; value: VideoStatus }>({
-    id: active.id,
-    value: active.status,
-  });
-  const watched = (status.id === subject.id ? status.value : subject.status) === "watched";
+  const [marks, setMarks] = useState<Record<string, VideoStatus>>({});
+  const watched = (marks[subject.id] ?? subject.status) === "watched";
   const setWatched = (on: boolean) => {
     const next = on ? "watched" : "new";
-    setStatus({ id: subject.id, value: next });
+    setMarks((m) => ({ ...m, [subject.id]: next }));
     onState(subject.id, next, subject);
   };
 
@@ -722,8 +723,14 @@ export default function PlayerModal({
   // Turned off on this instance (a daily limit of 0): no tab, no button — nothing that could only
   // be refused.
   const relatedOn = useMe().related_enabled;
-  const playRelated = (v: Video, startAt: number) => {
+  const playRelated = (v: Video, startAt: number | null) => {
     setRelatedOpen(false);
+    // The video already playing (its row stays in the list): a new player for the same id would
+    // never be built (one per video), so a Restart is a seek, and a plain pick just keeps playing.
+    if (v.id === subject.id) {
+      if (startAt != null) seekTo(startAt);
+      return;
+    }
     setRelated({ video: v, startAt });
   };
   const descPop = useAnchoredPopover({
@@ -762,6 +769,15 @@ export default function PlayerModal({
   }, []);
 
   useKeyScope("ytPlayer");
+  // Its keys wait under a layer above it (the drawer, a dialog — see onPlayerKey), so the help sheet
+  // opened there must not list them.
+  useEffect(() => {
+    setScopeCoveredProbe(
+      "ytPlayer",
+      () => layerIdRef.current != null && anyBlockingLayerAbove(layerIdRef.current),
+    );
+    return () => setScopeCoveredProbe("ytPlayer", null);
+  }, []);
 
   // Keyboard shortcuts. The chords live in the shared keymap (`ytPlayer`
   // scope) so the help sheet lists them; only the behaviour behind each id is here.
@@ -888,6 +904,7 @@ export default function PlayerModal({
   useYtProgress({
     activeId: subject.id,
     resumeAt: subjectResume,
+    exactStart: related?.startAt != null,
     mountRef,
     playerRef,
     currentIdRef,

frontend/src/features/player/RelatedVideos.dom.test.tsx

@@ -25,6 +25,8 @@ import { RelatedVideos } from "./RelatedVideos";
 import { api, HttpError, type RelatedVideo, type Video } from "../../lib/api";
 import { clearAll, getNotifications } from "../../lib/notifications";
 import { qk } from "../../lib/queryKeys";
+import { setHintsEnabled } from "../../lib/hints";
+import { writeVideoState } from "../video/videoWrites";
 
 beforeAll(() => {
   class Stub {
@@ -65,7 +67,7 @@ const page = (items: RelatedVideo[], next: string | null = null) => ({
 });
 
 function setup(
-  onPlay: (v: Video, startAt: number) => void = () => {},
+  onPlay: (v: Video, startAt: number | null) => void = () => {},
   onWrite?: (write: Promise<unknown>) => void,
 ) {
   vi.spyOn(api, "comfortPins").mockResolvedValue({ items: [] } as never);
@@ -116,12 +118,17 @@ describe("RelatedVideos", () => {
     expect(saved).toHaveBeenCalledWith({ relatedRegion: "hu" });
   });
 
+  // A plain pick resumes (null: the player knows the freshest position); the row's own position
+  // travels on the video it hands over.
   it("plays a row from where the user left it", async () => {
     vi.spyOn(api, "related").mockResolvedValue(page([row("A", { position_seconds: 95 })]));
     const onPlay = vi.fn();
     setup(onPlay);
     fireEvent.click(await title("Video A"));
-    expect(onPlay).toHaveBeenCalledWith(expect.objectContaining({ id: "A" }), 95);
+    expect(onPlay).toHaveBeenCalledWith(
+      expect.objectContaining({ id: "A", position_seconds: 95 }),
+      null,
+    );
   });
 
   it("drops a video hidden here at once, and brings it back when the server refuses", async () => {
@@ -308,6 +315,71 @@ describe("RelatedVideos", () => {
     expect(await screen.findByText("player.related.followed")).toBeTruthy();
   });
 
+  // An infinite query builds its next page from the pages it read when that fetch started: a mark
+  // that landed in between was dropped with them, for the session.
+  it("keeps a hide that landed while Show more was on its way", async () => {
+    let land: (p: ReturnType<typeof page>) => void = () => {};
+    vi.spyOn(api, "related")
+      .mockResolvedValueOnce(page([row("A"), row("C")], "CUR1"))
+      .mockReturnValueOnce(new Promise((r) => (land = r)) as never);
+    const write = vi.spyOn(api, "setState").mockResolvedValue({ ok: true } as never);
+    setup();
+    await title("Video A");
+    fireEvent.click(screen.getByRole("button", { name: "player.related.more" }));
+    fireEvent.contextMenu((await title("Video A")).closest("[data-video-id]")!);
+    fireEvent.click(menuItem("card.hide"));
+    await waitFor(() => expect(write).toHaveBeenCalledWith("A", "hidden"));
+    await act(async () => {});
+    await act(async () => land(page([row("B")])));
+    await title("Video B");
+    expect(titles()).toEqual(["Video C", "Video B"]);
+  });
+
+  // The Notification Center's undo, the feed's reset, a card elsewhere: every write reaches it.
+  it("follows a video's state written anywhere else", async () => {
+    vi.spyOn(api, "related").mockResolvedValue(page([row("A"), row("B")]));
+    vi.spyOn(api, "setState").mockResolvedValue({ ok: true } as never);
+    const { qc } = setup();
+    await title("Video A");
+    await act(async () => void (await writeVideoState(qc, "A", "hidden")));
+    await waitFor(() => expect(titles()).toEqual(["Video B"]));
+    await act(async () => void (await writeVideoState(qc, "A", "new")));
+    await waitFor(() => expect(titles()).toEqual(["Video A", "Video B"]));
+  });
+
+  // Show more is the request Retry would make: refused for good, it is not offered either.
+  it("offers no Show more once the next page was refused for good", async () => {
+    vi.spyOn(api, "related")
+      .mockResolvedValueOnce(page([row("A")], "CUR1"))
+      .mockRejectedValueOnce(
+        new HttpError(429, "Limit", { code: "refused", reason: "related_daily_limit", limit: 3 }),
+      );
+    setup();
+    await title("Video A");
+    fireEvent.click(screen.getByRole("button", { name: "player.related.more" }));
+    expect((await screen.findByRole("alert")).textContent).toContain("Limit");
+    expect(screen.queryByRole("button", { name: "player.related.more" })).toBeNull();
+    expect(screen.queryByRole("button", { name: "common.retry" })).toBeNull();
+    expect(titles()).toEqual(["Video A"]);
+  });
+
+  it("names the followed mark on hover with hints turned off too", async () => {
+    setHintsEnabled(false);
+    try {
+      vi.spyOn(api, "related").mockResolvedValue(page([row("A", { followed: true })]));
+      setup();
+      await title("Video A");
+      const mark = screen.getByRole("img", { name: "player.related.followed" });
+      fireEvent.mouseEnter(mark.parentElement!);
+      fireEvent.pointerEnter(mark.parentElement!, { pointerType: "mouse" });
+      expect(await screen.findByText("player.related.followed")).toBeTruthy();
+    } catch (e) {
+      setHintsEnabled(true);
+      throw e;
+    }
+    setHintsEnabled(true);
+  });
+
   it("says when nothing is left that the user has not seen", async () => {
     vi.spyOn(api, "related").mockResolvedValue(page([]));
     setup();

frontend/src/features/player/RelatedVideos.tsx

@@ -3,11 +3,18 @@ import { useTranslation } from "react-i18next";
 import { useInfiniteQuery, useQueryClient } from "@tanstack/react-query";
 import { CircleCheck } from "lucide-react";
 
-import { api, HttpError, type RelatedRegion, type Video, type VideoStatus } from "../../lib/api";
+import {
+  api,
+  HttpError,
+  refusalReason,
+  type RelatedRegion,
+  type Video,
+  type VideoStatus,
+} from "../../lib/api";
 import { qk } from "../../lib/queryKeys";
 import { nextPageOnClick } from "../../lib/nextPage";
 import { usePref, type UsePrefOptions } from "../../lib/usePref";
-import { patchRelated } from "../../lib/progressCache";
+import { useVideoMarks } from "../../lib/progressCache";
 import { notifyActionError } from "../../lib/actionErrors";
 import { Button } from "../../components/ui/Button";
 import SegmentedToggle from "../../components/ui/SegmentedToggle";
@@ -18,6 +25,7 @@ import Tooltip from "../../components/ui/Tooltip";
 import VideoCard from "../video/VideoCard";
 import { VideoMenu } from "../video/VideoMenu";
 import { announceVideoState } from "../video/stateNotice";
+import { writeVideoState, writeWatchLater } from "../video/videoWrites";
 
 /** Which list YouTube fills in — on the video's topic or with what trends in Hungary — is a mood,
  *  decided at the list, and the account keeps the last one (the owner's pick). */
@@ -33,9 +41,7 @@ const isSeen = (v: Video) => v.status === "watched" || v.status === "hidden";
 /** The refusals a retry cannot answer: the day's cap (tomorrow does), the feature turned off on
  *  this instance and the shared budget spent (the admin, or tomorrow). */
 const FINAL_REASONS = new Set(["related_daily_limit", "related_disabled", "quota"]);
-const isFinal = (e: unknown) =>
-  e instanceof HttpError &&
-  FINAL_REASONS.has((e.detailData as { reason?: string } | undefined)?.reason ?? "");
+const isFinal = (e: unknown) => FINAL_REASONS.has(refusalReason(e) ?? "");
 
 // A write not yet confirmed: its change shows at once, and leaves when the server answers.
 type Pending = { seq: number; id: string; change: Partial<Video> };
@@ -49,7 +55,8 @@ export function RelatedVideos({
   onWrite,
 }: {
   videoId: string;
-  onPlay: (v: Video, startAt: number) => void;
+  /** `startAt` null resumes the video where it was left; a number (Restart's 0) starts there. */
+  onPlay: (v: Video, startAt: number | null) => void;
   /** Each write this list makes, for the host's player session (see PlayerModal `onWrite`). */
   onWrite?: (write: Promise<unknown>) => void;
 }) {
@@ -83,11 +90,10 @@ export function RelatedVideos({
   const onState = (id: string, status: VideoStatus) => {
     const v = rows.find((x) => x.id === id);
     const seq = begin(id, { status });
-    const write = api.setState(id, status);
+    const write = writeVideoState(qc, id, status);
     onWrite?.(write);
     write
       .then(() => {
-        patchRelated(qc, id, { status });
         settle(seq);
         // Stale-mark the feed, as its own marks do: the video may be in it too.
         void qc.invalidateQueries({ queryKey: qk.feed(), refetchType: "none" });
@@ -101,11 +107,10 @@ export function RelatedVideos({
 
   const onToggleSave = (id: string, saved: boolean) => {
     const seq = begin(id, { saved });
-    const write = saved ? api.watchLaterAdd(id) : api.watchLaterRemove(id);
+    const write = writeWatchLater(qc, id, saved);
     onWrite?.(write);
     write
       .then(() => {
-        patchRelated(qc, id, { saved });
         settle(seq);
         void qc.invalidateQueries({ queryKey: qk.playlists() });
         void qc.invalidateQueries({ queryKey: qk.playlist() });
@@ -119,12 +124,15 @@ export function RelatedVideos({
       });
   };
 
-  const open = (v: Video, startAt?: number | null) => onPlay(v, startAt ?? v.position_seconds);
+  const open = (v: Video, startAt?: number | null) => onPlay(v, startAt ?? null);
   const menu = useContextMenu<Video>();
   const openId = menu.open ? menu.target?.id : undefined;
 
+  // What this session confirmed about a row (here or anywhere else), then what is on its way.
+  const marks = useVideoMarks();
   const rows = (query.data?.pages ?? [])
     .flatMap((p) => p.items)
+    .map((v) => (marks[v.id] ? { ...v, ...marks[v.id] } : v))
     .map((v) => pending.reduce((acc, w) => (w.id === v.id ? { ...acc, ...w.change } : acc), v))
     .filter((v) => !isSeen(v));
   const followed = new Set(
@@ -139,7 +147,8 @@ export function RelatedVideos({
         : null;
   // A refused page is the one to try again: with pages loaded, a refetch started over from the first
   // (another scrape and another slot) instead of asking for the page that failed.
-  const retry = isFinal(query.error)
+  const final = isFinal(query.error);
+  const retry = final
     ? undefined
     : query.data?.pages.length
       ? () => void query.fetchNextPage(nextPageOnClick(query.isFetchingNextPage))
@@ -203,7 +212,8 @@ export function RelatedVideos({
               />
             ))}
           </NavGrid>
-          {query.hasNextPage && (
+          {/* Show more is the same request a Retry makes: refused for good, neither is offered. */}
+          {query.hasNextPage && !final && (
             <div className="mt-3 flex justify-center">
               <Button
                 variant="outline"

frontend/src/features/video/videoWrites.contract.test.ts

@@ -0,0 +1,34 @@
+import { readdirSync, readFileSync } from "node:fs";
+import { describe, expect, it } from "vitest";
+
+// The whole app source: a state write can be made from any page.
+const root = new URL("../../", import.meta.url);
+const sources = () =>
+  readdirSync(root, { recursive: true, encoding: "utf8" })
+    .map((f) => f.replace(/\\/g, "/"))
+    .filter((f) => /\.tsx?$/.test(f) && !f.includes(".test."))
+    .map((f) => ({ f, src: readFileSync(new URL(f, root), "utf8") }));
+
+// The api's own definitions of these writes, and the one module that may call them.
+const ALLOWED = new Set([
+  "lib/api/feed.ts",
+  "lib/api/playlists.ts",
+  "features/video/videoWrites.ts",
+]);
+
+// A related list and a live search are never refetched, so a state or Watch-later write that does
+// not reach them (`markVideo`) leaves them showing the old mark for the session. videoWrites makes
+// those writes and the mark together; a direct api call skips the mark.
+describe("a video's state and Watch-later writes", () => {
+  it("go through features/video/videoWrites, never the api directly", () => {
+    const offenders = sources()
+      .filter(({ f }) => !ALLOWED.has(f))
+      // Only a call on the api object counts (React's own `setState` is not ours); the dot may sit
+      // on the next line of a chain.
+      .filter(({ src }) =>
+        /\bapi\s*\.\s*(setState|clearState|watchLaterAdd|watchLaterRemove)\(/.test(src),
+      )
+      .map(({ f }) => f);
+    expect(offenders).toEqual([]);
+  });
+});

frontend/src/features/video/videoWrites.dom.test.ts

@@ -0,0 +1,47 @@
+// @vitest-environment jsdom
+//
+// Each write reaches the lists that are never refetched once the server has it — and not before:
+// a refused write leaves them as they were.
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { QueryClient } from "@tanstack/react-query";
+
+import { api } from "../../lib/api";
+import { qk } from "../../lib/queryKeys";
+import { resetVideoState, writeVideoState, writeWatchLater } from "./videoWrites";
+
+afterEach(() => vi.restoreAllMocks());
+
+const marks = (qc: QueryClient) => qc.getQueryData(qk.videoMarks());
+
+describe("videoWrites", () => {
+  it("marks a state written", async () => {
+    vi.spyOn(api, "setState").mockResolvedValue({ ok: true } as never);
+    const qc = new QueryClient();
+    await writeVideoState(qc, "X", "hidden");
+    expect(marks(qc)).toEqual({ X: { status: "hidden" } });
+  });
+
+  it("marks a reset as new, from the start", async () => {
+    vi.spyOn(api, "clearState").mockResolvedValue({ ok: true } as never);
+    const qc = new QueryClient();
+    await resetVideoState(qc, "X");
+    expect(marks(qc)).toEqual({ X: { status: "new", position_seconds: 0 } });
+  });
+
+  it("marks a Watch-later save and its removal", async () => {
+    vi.spyOn(api, "watchLaterAdd").mockResolvedValue({ ok: true } as never);
+    vi.spyOn(api, "watchLaterRemove").mockResolvedValue({ ok: true } as never);
+    const qc = new QueryClient();
+    await writeWatchLater(qc, "X", true);
+    expect(marks(qc)).toEqual({ X: { saved: true } });
+    await writeWatchLater(qc, "X", false);
+    expect(marks(qc)).toEqual({ X: { saved: false } });
+  });
+
+  it("marks nothing the server refused", async () => {
+    vi.spyOn(api, "setState").mockRejectedValue(new Error("offline"));
+    const qc = new QueryClient();
+    await expect(writeVideoState(qc, "X", "hidden")).rejects.toThrow("offline");
+    expect(marks(qc)).toBeUndefined();
+  });
+});

frontend/src/features/video/videoWrites.ts

@@ -0,0 +1,34 @@
+import type { QueryClient } from "@tanstack/react-query";
+
+import { api, type VideoStatus } from "../../lib/api";
+import { markVideo } from "../../lib/progressCache";
+
+// A video's user state and its Watch-later mark, written to the server and — once it has the
+// change — into the lists that are never refetched (`markVideo`: every related list, every live
+// search). These are the ONE way to make those writes, and `videoWrites.contract.test.ts` holds it:
+// four writes that called the api directly (the Notification Center's undo, the feed's reset, the
+// feed's and Home's Watch-later toggles) left a related list hiding a video the user had un-hidden,
+// or showing it unsaved after a save. Each returns the server's answer, so a caller keeps its own
+// optimistic layer, notices and rollback.
+
+export function writeVideoState(qc: QueryClient, id: string, status: VideoStatus) {
+  return api.setState(id, status).then((r) => {
+    markVideo(qc, id, { status });
+    return r;
+  });
+}
+
+/** Back to pristine: the state row and its resume position both go. */
+export function resetVideoState(qc: QueryClient, id: string) {
+  return api.clearState(id).then((r) => {
+    markVideo(qc, id, { status: "new", position_seconds: 0 });
+    return r;
+  });
+}
+
+export function writeWatchLater(qc: QueryClient, id: string, saved: boolean) {
+  return (saved ? api.watchLaterAdd(id) : api.watchLaterRemove(id)).then((r) => {
+    markVideo(qc, id, { saved });
+    return r;
+  });
+}

frontend/src/i18n/locales/en/errors.json

@@ -189,7 +189,7 @@
     "recipient_required": "A recipient email is required",
     "registration_closed": "Registration is currently closed",
     "related_disabled": "Related videos are turned off on this instance.",
-    "related_daily_limit": "You've opened today's limit of related lists ({{limit}}). Try again tomorrow.",
+    "related_daily_limit": "You've reached today's related videos limit ({{limit}} requests — each list and each Show more counts one). Try again tomorrow.",
     "search_disabled": "Live YouTube search is turned off on this instance.",
     "search_daily_limit": "You've reached today's YouTube search limit ({{limit}}). Try again tomorrow.",
     "search_term_required": "Enter something to search for",

frontend/src/i18n/locales/hu/errors.json

@@ -189,7 +189,7 @@
     "recipient_required": "Adj meg egy címzett e-mail címet",
     "registration_closed": "A regisztráció jelenleg zárva van",
     "related_disabled": "A kapcsolódó videók ki vannak kapcsolva ezen a példányon.",
-    "related_daily_limit": "Elérted a mai kapcsolódó listák korlátját ({{limit}}). Próbáld holnap.",
+    "related_daily_limit": "Elérted a kapcsolódó videók mai korlátját ({{limit}} kérés — minden lista és minden „Mutass többet” egynek számít). Próbáld holnap.",
     "search_disabled": "Az élő YouTube-keresés ki van kapcsolva ezen a példányon.",
     "search_daily_limit": "Elérted a mai YouTube-keresési korlátot ({{limit}}). Próbáld holnap.",
     "search_term_required": "Írj be egy keresőkifejezést",

frontend/src/lib/api.ts

@@ -6,10 +6,10 @@
 //   3. spreads each domain's method slice into the single `api` object consumers call.
 // A new endpoint therefore has nowhere to land except a domain module — the interleave that
 // motivated the split cannot re-grow here. (lib/api/facade.test.ts guards that invariant.)
-import { HttpError, setUnauthorizedHandler } from "./api/core";
+import { HttpError, refusalReason, setUnauthorizedHandler } from "./api/core";
 
 // Re-export the shared HTTP machinery so consumers keep importing these from "./api" unchanged.
-export { HttpError, setUnauthorizedHandler };
+export { HttpError, refusalReason, setUnauthorizedHandler };
 
 import { accountApi } from "./api/account";
 export type * from "./api/account";

frontend/src/lib/api/core.ts

@@ -65,6 +65,12 @@ export class HttpError extends Error {
   }
 }
 
+/** The structured refusal's reason (`{ code, reason }`), when the server gave one. */
+export const refusalReason = (err: unknown): string | undefined =>
+  err instanceof HttpError
+    ? (err.detailData as { reason?: string } | undefined)?.reason
+    : undefined;
+
 // Localize a STRUCTURED server error ({ code, reason, ... }) into the user's language. FastAPI
 // usually returns a plain string `detail`, but some routes (e.g. download quota/edit) return a
 // structured object with an i18n reason key + numbers so HU/DE users don't get hardcoded English

frontend/src/lib/keymap.ts

@@ -488,17 +488,31 @@ export const setListInTopLayerProbe = (probe: () => boolean): void => {
   listInTopLayer = probe;
 };
 
+// A surface whose keys wait while a layer sits above it (the YouTube player under its related
+// drawer or a dialog: every key but Escape is the layer's then). Its rows would promise keys that do
+// nothing, so the sheet leaves the scope out — asked at the same moment as `helpOverLayer`.
+const coveredProbes = new Map<KeyScope, () => boolean>();
+export const setScopeCoveredProbe = (scope: KeyScope, probe: (() => boolean) | null): void => {
+  if (probe) coveredProbes.set(scope, probe);
+  else coveredProbes.delete(scope);
+};
+const helpCovered = createStore<ReadonlySet<KeyScope>>(new Set());
+
 export const closeKeyboardHelp = (): void => helpOpen.set(false);
 export const toggleKeyboardHelp = (): void => {
   const next = !helpOpen.get();
-  if (next)
+  if (next) {
     helpOverLayer.set(!anyBlockingLayer() ? "page" : listInTopLayer() ? "layerWithList" : "layer");
+    helpCovered.set(new Set([...coveredProbes].filter(([, covered]) => covered()).map(([s]) => s)));
+  }
   helpOpen.set(next);
 };
 /** Subscribe to whether the sheet is showing (the Plex player suppresses wheel-volume under it). */
 export const useKeyboardHelpOpen = (): boolean => helpOpen.useValue();
 /** What the sheet was opened over (see `helpOverLayer`). */
 export const useKeyboardHelpOverLayer = (): HelpOver => helpOverLayer.useValue();
+/** The surfaces a layer covered when the sheet opened (see `setScopeCoveredProbe`). */
+export const useKeyboardHelpCovered = (): ReadonlySet<KeyScope> => helpCovered.useValue();
 
 // The modules this account can reach — published by `useGlobalKeymap`, read by the `g` chords and
 // by the sheet (which drops the chord of a gated module rather than promise a page that isn't there).

frontend/src/lib/playerModalHooks.apiload.dom.test.tsx

@@ -30,6 +30,7 @@ function mountPlayer(setPlayerError: (code: number | null) => void) {
     useYtProgress({
       activeId: VID,
       resumeAt: 0,
+      exactStart: false,
       mountRef: { current: mount },
       playerRef: createRef<YTPlayer>() as RefObject<YTPlayer | null>,
       currentIdRef: { current: VID },

frontend/src/lib/playerModalHooks.progress.dom.test.tsx

@@ -72,6 +72,7 @@ function mountPlayer(qc: QueryClient, sessionPos: Map<string, number>) {
     useYtProgress({
       activeId: VID,
       resumeAt: 748,
+      exactStart: false,
       mountRef: { current: mount },
       playerRef: createRef<YTPlayer>() as RefObject<YTPlayer | null>,
       currentIdRef: { current: VID },

frontend/src/lib/playerModalHooks.ts

@@ -339,6 +339,7 @@ function playerTimes(p: YTPlayer | null): { cur: number; dur: number } | null {
 export function useYtProgress({
   activeId,
   resumeAt,
+  exactStart,
   mountRef,
   playerRef,
   currentIdRef,
@@ -355,6 +356,8 @@ export function useYtProgress({
 }: {
   activeId: string;
   resumeAt: number;
+  // `resumeAt` is where the user asked to start, so it beats a position this session stored.
+  exactStart: boolean;
   mountRef: RefObject<HTMLDivElement | null>;
   playerRef: RefObject<YTPlayer | null>;
   currentIdRef: RefObject<string>;
@@ -378,6 +381,7 @@ export function useYtProgress({
   // the end of the effect).
   const itemSnapshot = useEffectEvent(() => ({
     resumeAt,
+    exactStart,
     setWatched,
     setPlayerError,
     setLiveData,
@@ -392,6 +396,7 @@ export function useYtProgress({
     const id = activeId;
     const {
       resumeAt,
+      exactStart,
       setWatched,
       setPlayerError,
       setLiveData,
@@ -401,7 +406,8 @@ export function useYtProgress({
       qc,
     } = itemSnapshot();
     // A position this session already stored for the item beats the queue's snapshot of it.
-    const startAt = sessionPosRef.current.get(id) ?? resumeAt;
+    // …unless the user asked for a start of their own (Restart on a related row).
+    const startAt = exactStart ? resumeAt : (sessionPosRef.current.get(id) ?? resumeAt);
     autoMarkedRef.current = false;
     setPlayerError(null);
 

frontend/src/lib/progressCache.test.ts

@@ -0,0 +1,38 @@
+// What a confirmed mark reaches. A related list and a live YouTube search are never refetched (a
+// scrape and a slot of the day's cap, or 100 quota units), so the mark is written into them; and it is
+// kept apart from them too, where a page landing later cannot take it back.
+import { describe, expect, it } from "vitest";
+import { QueryClient } from "@tanstack/react-query";
+
+import { markVideo, patchCachedProgress } from "./progressCache";
+import { qk } from "./queryKeys";
+import type { Video } from "./api";
+
+const v = (id: string): Video =>
+  ({ id, status: "new", saved: false, position_seconds: 0 }) as Video;
+const pages = (...ids: string[]) => ({ pages: [{ items: ids.map(v) }], pageParams: [null] });
+const items = (qc: QueryClient, key: readonly unknown[]) =>
+  (qc.getQueryData(key) as { pages: { items: Video[] }[] }).pages[0]!.items;
+
+describe("markVideo", () => {
+  it("writes the mark into every live search and every related list", () => {
+    const qc = new QueryClient();
+    qc.setQueryData(qk.ytSearch("cats", 20), pages("X", "Y"));
+    qc.setQueryData(qk.related("A", "topical"), pages("X"));
+    markVideo(qc, "X", { status: "watched" });
+    expect(items(qc, qk.ytSearch("cats", 20)).map((r) => r.status)).toEqual(["watched", "new"]);
+    expect(items(qc, qk.related("A", "topical"))[0]!.status).toBe("watched");
+  });
+
+  it("keeps the mark apart from the lists, for the session", () => {
+    const qc = new QueryClient();
+    markVideo(qc, "X", { status: "hidden" });
+    markVideo(qc, "X", { saved: true });
+    patchCachedProgress(qc, new Map([["X", 90]]));
+    expect(qc.getQueryData(qk.videoMarks())).toEqual({
+      X: { status: "hidden", saved: true, position_seconds: 90 },
+    });
+    // Nothing observes it before a related list opens: it must not be collected meanwhile.
+    expect(qc.getQueryCache().find({ queryKey: qk.videoMarks() })?.options.gcTime).toBe(Infinity);
+  });
+});

frontend/src/lib/progressCache.ts

@@ -1,4 +1,4 @@
-import type { QueryClient } from "@tanstack/react-query";
+import { useQuery, useQueryClient, type QueryClient, type QueryKey } from "@tanstack/react-query";
 import { qk } from "./queryKeys";
 import type { Video } from "./api";
 
@@ -40,17 +40,67 @@ export const progressFlushes = (): Promise<unknown>[] => [...flushes];
 
 export function patchCachedProgress(qc: QueryClient, positions: Map<string, number>): void {
   if (positions.size === 0) return;
+  // Prefix keys: every filter combination of the feed, every playlist detail, every live YouTube
+  // search and every related list — their rows come from the same projection, carry the same
+  // per-user position, and open the same player, so leaving one out left the rewind in place on that
+  // surface. (Patched, never invalidated: a refetch of an API-sourced search page spends 100 quota
+  // units, a related list's a scrape and a slot of the day's cap.)
+  patchLists(qc, [qk.feed(), qk.playlist(), qk.ytSearch(), qk.related()], (v) => {
+    const pos = positions.get(v.id);
+    return pos === undefined || v.position_seconds === pos ? v : { ...v, position_seconds: pos };
+  });
+  for (const [id, pos] of positions) remember(qc, id, { position_seconds: pos });
+}
 
+/** Write one video's confirmed change (its status, its Watch-later mark) into the lists that are
+ *  never refetched: every related list (both regions', every opened video's) and every live
+ *  YouTube search — another scrape and a slot of the day's cap, or 100 quota units, each. A video
+ *  marked anywhere else (a feed card, a playlist, the player, the Notification Center's undo) still
+ *  showed there unmarked. Called by `features/video/videoWrites`, which every such write goes
+ *  through (its contract test holds that). */
+export function markVideo(qc: QueryClient, id: string, change: Partial<Video>): void {
+  patchLists(qc, [qk.ytSearch(), qk.related()], (v) => (v.id === id ? { ...v, ...change } : v));
+  remember(qc, id, change);
+}
+
+// What this session confirmed about each video, kept APART from the lists that show it. A list's
+// own cache cannot hold it alone: an infinite query builds its next page's data from the pages it
+// read when that fetch STARTED (react-query's infiniteQueryBehavior), so a mark confirmed while a
+// related list's Show more was on its way vanished when the page landed — for the session, since
+// those lists are never refetched. The related list lays these over its rows (`useVideoMarks`).
+type Marks = Record<string, Partial<Video>>;
+
+function remember(qc: QueryClient, id: string, change: Partial<Video>): void {
+  // Kept while the app is open, observed or not: a mark made before any related list was opened
+  // must still be there when one is.
+  qc.setQueryDefaults(qk.videoMarks(), { staleTime: Infinity, gcTime: Infinity });
+  qc.setQueryData<Marks>(qk.videoMarks(), (m) => ({ ...m, [id]: { ...m?.[id], ...change } }));
+}
+
+/** This session's confirmed marks, per video id (see `markVideo`). */
+export function useVideoMarks(): Marks {
+  const qc = useQueryClient();
+  return useQuery({
+    queryKey: qk.videoMarks(),
+    // Nothing to fetch: the marks are what this session wrote, and the cache is where they live.
+    queryFn: () => qc.getQueryData<Marks>(qk.videoMarks()) ?? {},
+    initialData: {},
+    staleTime: Infinity,
+    gcTime: Infinity,
+  }).data;
+}
+
+/** Apply `edit` to every row of every cached list under `keys` (prefix keys), keeping each untouched
+ *  page's and list's identity — so an unchanged list does not re-render every card behind the
+ *  open player. */
+function patchLists(qc: QueryClient, keys: readonly QueryKey[], edit: (v: Video) => Video): void {
   const patchList = (items: Video[]): Video[] => {
     let changed = false;
     const next = items.map((v) => {
-      const pos = positions.get(v.id);
-      if (pos === undefined || v.position_seconds === pos) return v;
-      changed = true;
-      return { ...v, position_seconds: pos };
+      const out = edit(v);
+      if (out !== v) changed = true;
+      return out;
     });
-    // Keep the previous array identity when nothing moved, so an untouched list does not
-    // re-render every card behind the open player.
     return changed ? next : items;
   };
 
@@ -74,31 +124,5 @@ export function patchCachedProgress(qc: QueryClient, positions: Map<string, numb
     return old;
   };
 
-  // Prefix keys: every filter combination of the feed, every playlist detail, every live YouTube
-  // search and every related list — their rows come from the same projection, carry the same
-  // per-user position, and open the same player, so leaving one out left the rewind in place on that
-  // surface. (Patched, never invalidated: a refetch of an API-sourced search page spends 100 quota
-  // units, a related list's a scrape and a slot of the day's cap.)
-  qc.setQueriesData<Cached>({ queryKey: qk.feed() }, patch);
-  qc.setQueriesData<Cached>({ queryKey: qk.playlist() }, patch);
-  qc.setQueriesData<Cached>({ queryKey: qk.ytSearch() }, patch);
-  qc.setQueriesData<Cached>({ queryKey: qk.related() }, patch);
-}
-
-/** Write one video's change (its status, its Watch-later mark) into every cached related list —
- *  both regions', every opened video's. Those lists are never refetched (another scrape and a slot
- *  of the day's cap), and they leave out what the user has seen: a video marked anywhere else — a
- *  feed card, a playlist, the player itself — still showed in one opened again later. So every
- *  state write calls it once the server has the change. */
-export function patchRelated(qc: QueryClient, id: string, change: Partial<Video>): void {
-  qc.setQueriesData<Cached>({ queryKey: qk.related() }, (old) => {
-    if (!old?.pages) return old;
-    let changed = false;
-    const pages = old.pages.map((page) => {
-      if (!isItemList(page) || !page.items.some((v) => v.id === id)) return page;
-      changed = true;
-      return { ...page, items: page.items.map((v) => (v.id === id ? { ...v, ...change } : v)) };
-    });
-    return changed ? { ...old, pages } : old;
-  });
+  for (const queryKey of keys) qc.setQueriesData<Cached>({ queryKey }, patch);
 }

frontend/src/lib/queryKeys.ts

@@ -34,6 +34,8 @@ export const qk = {
   videoDetail: (id: string) => ["video-detail", id] as const,
   related: (id?: string, region?: string) =>
     id !== undefined ? (["related", id, region] as const) : (["related"] as const),
+  // This session's confirmed marks per video (lib/progressCache `markVideo`): no fetch behind it.
+  videoMarks: () => ["video-marks"] as const,
 
   // --- channels ---
   channels: () => ["channels"] as const,

frontend/src/modules/channels/WatchedVideosDialog.tsx

@@ -3,7 +3,7 @@ import { useTranslation } from "react-i18next";
 import { useQuery, useQueryClient } from "@tanstack/react-query";
 import { EyeOff, Play, UserPlus } from "lucide-react";
 import { qk } from "../../lib/queryKeys";
-import { patchRelated } from "../../lib/progressCache";
+import { writeVideoState } from "../../features/video/videoWrites";
 import { api, type Video, type VideoStatus, type WatchedChannel } from "../../lib/api";
 import { formatDate, formatDuration } from "../../lib/format";
 import { notifyActionError } from "../../lib/actionErrors";
@@ -54,8 +54,7 @@ export default function WatchedVideosDialog({
 
   // The player's watched / in-progress marks: saved, then shown on this list and the feed's.
   const onState = useStableCallback((id: string, status: VideoStatus) => {
-    api
-      .setState(id, status)
+    writeVideoState(qc, id, status)
       .then(() => {
         qc.setQueryData(
           key,
@@ -66,8 +65,6 @@ export default function WatchedVideosDialog({
             },
         );
         void qc.invalidateQueries({ queryKey: qk.feed() });
-        // The player's related lists are never refetched: the mark goes into them.
-        patchRelated(qc, id, { status });
       })
       .catch((e: unknown) => notifyActionError(e, t("errors.writeFailed.videoState")));
   });

frontend/src/modules/feed/Feed.tsx

@@ -22,14 +22,26 @@ import {
   type LucideIcon,
 } from "lucide-react";
 import { YouTubeIcon } from "../../lib/brandIcons";
-import { api, HttpError, type FeedFilters, type Video, type VideoStatus } from "../../lib/api";
+import {
+  api,
+  HttpError,
+  refusalReason,
+  type FeedFilters,
+  type Video,
+  type VideoStatus,
+} from "../../lib/api";
 import i18n from "../../i18n";
 import { notifyActionError } from "../../lib/actionErrors";
 import { announceVideoState, type NoticeVideo } from "../../features/video/stateNotice";
+import {
+  resetVideoState,
+  writeVideoState,
+  writeWatchLater,
+} from "../../features/video/videoWrites";
 import { notify } from "../../lib/notifications";
 import { useMe } from "../../lib/useMe";
 import { useDebounced } from "../../lib/useDebounced";
-import { patchCachedProgress, patchRelated, progressFlushes } from "../../lib/progressCache";
+import { patchCachedProgress, progressFlushes } from "../../lib/progressCache";
 import {
   buildSort,
   feedSortOptions,
@@ -124,6 +136,15 @@ const withoutWrite = <T,>(o: Overrides<T>, id: string, seq: number): Overrides<T
 // How many live-search results one fetch asks for; `Load more` pulls another batch of the same size.
 const YT_COUNTS = [20, 40, 60, 100] as const;
 
+// The live-search refusals a retry cannot answer: the day's cap, turned off on this instance, the
+// shared budget spent (ours, or YouTube's own) — tomorrow or the admin does.
+const SEARCH_FINAL_REASONS = new Set([
+  "search_daily_limit",
+  "search_disabled",
+  "quota_spent",
+  "quota",
+]);
+
 export default function Feed({
   filters,
   setFilters,
@@ -358,7 +379,7 @@ export default function Feed({
     (id: string, status: VideoStatus, video?: NoticeVideo) => {
       const seq = ++writeSeq.current;
       setOverrides((o) => ({ ...o, [id]: { value: status, seq } }));
-      const write = api.setState(id, status);
+      const write = writeVideoState(qc, id, status);
       trackSessionWrite(write);
       // Refetch once the server has the change so other views (e.g. Hidden) are in sync.
       // Announce the change only AFTER the server confirms it: a "Marked watched"/"Hidden"
@@ -373,7 +394,6 @@ export default function Feed({
           // storm (PERF-2). The next filter change / remount refetches fresh from the server.
           answered.current.add(seq);
           qc.invalidateQueries({ queryKey: qk.feed(), refetchType: "none" });
-          patchRelated(qc, id, { status });
           // The video the player is on may be none of this list's (a related one): it names itself.
           const v = video ?? loadedRef.current.find((x) => x.id === id);
           announceVideoState(id, status, v, () => onStateRef.current(id, "new"));
@@ -401,8 +421,7 @@ export default function Feed({
       const before = loadedRef.current.find((v) => v.id === id)?.position_seconds;
       patchCachedProgress(qc, new Map([[id, 0]]));
       resets.current.set(id, seq);
-      api
-        .clearState(id)
+      resetVideoState(qc, id)
         // Stale-mark only (see setState above): the optimistic override already reset the card.
         .then(() => {
           answered.current.add(seq);
@@ -423,7 +442,7 @@ export default function Feed({
     (id: string, saved: boolean) => {
       const seq = ++writeSeq.current;
       setSavedOverrides((o) => ({ ...o, [id]: { value: saved, seq } }));
-      (saved ? api.watchLaterAdd(id) : api.watchLaterRemove(id))
+      writeWatchLater(qc, id, saved)
         .then(() => {
           answered.current.add(seq);
           qc.invalidateQueries({ queryKey: qk.playlists() });
@@ -491,6 +510,9 @@ export default function Feed({
         : ytQuery.isError
           ? t("feed.yt.error")
           : null;
+    // A refusal a retry cannot answer (the day's cap, turned off, the shared budget): Load more —
+    // the same request — is not offered after it.
+    const ytFinal = SEARCH_FINAL_REASONS.has(refusalReason(ytQuery.error) ?? "");
     // The backend reports which source served the search; scrape spends no search quota, so we
     // drop the quota warning + "uses quota" wording in that mode.
     const zeroQuota = ytQuery.data?.pages?.[0]?.source === "scrape";
@@ -577,7 +599,7 @@ export default function Feed({
 
         {ytQuery.isLoading ? (
           <div className="py-16 text-center text-muted">{t("feed.yt.searching")}</div>
-        ) : ytError ? (
+        ) : ytError && !ytItems.length ? (
           <div className="py-16 text-center text-muted max-w-md mx-auto">{ytError}</div>
         ) : ytItems.length === 0 ? (
           <div className="py-16 text-center text-muted">{t("feed.yt.noResults")}</div>
@@ -594,7 +616,7 @@ export default function Feed({
               isFetching={false}
               fetchNextPage={() => {}}
             />
-            {ytQuery.hasNextPage && (
+            {ytQuery.hasNextPage && !ytFinal && (
               <div className="text-center pt-4">
                 <Button
                   variant="outline"
@@ -611,6 +633,13 @@ export default function Feed({
                 </Button>
               </div>
             )}
+            {/* A page that failed after others loaded: they stay, and the failure is said under
+                them (Load more above is the retry, when there is one). */}
+            {ytError && (
+              <StateMessage tone="error" compact className="mt-3">
+                {ytError}
+              </StateMessage>
+            )}
           </>
         )}
 

frontend/src/modules/feed/Feed.ytLoadMore.dom.test.tsx

@@ -0,0 +1,122 @@
+// @vitest-environment jsdom
+//
+// A live YouTube search's Load more that fails. The results already read stay on screen and the
+// failure is said under them; before, the whole pane turned into the error text. Load more is the
+// retry where trying again can help, and is not offered after a refusal it cannot answer (the day's
+// cap, the feature turned off, the shared budget).
+import { describe, it, expect, vi, beforeAll, afterEach } from "vitest";
+import { render, screen, fireEvent, waitFor, cleanup } from "@testing-library/react";
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+
+vi.mock("react-i18next", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("react-i18next")>()),
+  useTranslation: () => ({ t: (key: string) => key, i18n: { language: "en" } }),
+}));
+vi.mock("../../features/wizard/wizardContext", () => ({
+  useWizard: () => ({ openWizard: vi.fn() }),
+}));
+vi.mock("./VirtualFeed", () => ({
+  default: ({ items }: { items: { id: string; title: string }[] }) => (
+    <ol aria-label="results">
+      {items.map((v) => (
+        <li key={v.id}>{v.title}</li>
+      ))}
+    </ol>
+  ),
+}));
+
+import Feed from "./Feed";
+import { api, DEFAULT_TAG_MODES, HttpError, type FeedFilters, type Video } from "../../lib/api";
+import { qk } from "../../lib/queryKeys";
+
+beforeAll(() => {
+  class Stub {
+    observe() {}
+    unobserve() {}
+    disconnect() {}
+    takeRecords() {
+      return [];
+    }
+  }
+  globalThis.ResizeObserver ??= Stub as unknown as typeof ResizeObserver;
+  globalThis.IntersectionObserver ??= Stub as unknown as typeof IntersectionObserver;
+});
+afterEach(() => {
+  cleanup();
+  vi.restoreAllMocks();
+});
+
+const FILTERS: FeedFilters = {
+  tags: [],
+  tagModes: DEFAULT_TAG_MODES,
+  channelIds: [],
+  q: "",
+  sort: "newest",
+  scope: "my",
+  includeNormal: true,
+  includeShorts: false,
+  includeLive: false,
+  show: "unwatched",
+};
+
+const hit = (id: string): Video =>
+  ({
+    id,
+    title: `hit ${id}`,
+    channel_id: "UCx",
+    channel_title: "Channel",
+    status: "new",
+    position_seconds: 0,
+    published_at: "2026-01-01T00:00:00Z",
+    watch_url: `https://www.youtube.com/watch?v=${id}`,
+  }) as unknown as Video;
+
+function setup(failure: HttpError) {
+  vi.spyOn(api, "searchYoutube")
+    .mockResolvedValueOnce({ items: [hit("a")], next_cursor: "c2", source: "scrape" } as never)
+    .mockRejectedValueOnce(failure);
+  const qc = new QueryClient({ defaultOptions: { queries: { retry: false } } });
+  qc.setQueryData(qk.me(), { id: 1, can_write: true, prefs: {} });
+  render(
+    <QueryClientProvider client={qc}>
+      <Feed
+        filters={FILTERS}
+        setFilters={() => {}}
+        view="cards"
+        setView={() => {}}
+        canRead
+        ytSearch="lemmino"
+        onYtSearch={() => {}}
+        onExitYtSearch={() => {}}
+      />
+    </QueryClientProvider>,
+  );
+}
+
+const loadMore = () => screen.queryByRole("button", { name: "feed.yt.loadMoreFree" });
+
+describe("Feed — a live search's Load more that fails", () => {
+  it("keeps the results read, says why under them, and offers Load more again", async () => {
+    setup(
+      new HttpError(422, "YouTube isn't reachable", { code: "youtube", reason: "unavailable" }),
+    );
+    fireEvent.click(await screen.findByRole("button", { name: "feed.yt.loadMoreFree" }));
+    expect(await screen.findByText("YouTube isn't reachable")).toBeTruthy();
+    expect(screen.getByRole("list", { name: "results" }).textContent).toContain("hit a");
+    expect(loadMore()).toBeTruthy();
+  });
+
+  it("offers no Load more after a refusal a retry cannot answer", async () => {
+    setup(
+      new HttpError(429, "Today's limit", {
+        code: "refused",
+        reason: "search_daily_limit",
+        limit: 2,
+      }),
+    );
+    fireEvent.click(await screen.findByRole("button", { name: "feed.yt.loadMoreFree" }));
+    expect(await screen.findByText("Today's limit")).toBeTruthy();
+    expect(screen.getByRole("list", { name: "results" }).textContent).toContain("hit a");
+    await waitFor(() => expect(loadMore()).toBeNull());
+  });
+});

frontend/src/modules/home/Home.tsx

@@ -14,7 +14,6 @@ import {
   Star,
 } from "lucide-react";
 import { qk } from "../../lib/queryKeys";
-import { patchRelated } from "../../lib/progressCache";
 import { plexLang } from "../../i18n";
 import {
   api,
@@ -54,6 +53,7 @@ import SegmentedToggle from "../../components/ui/SegmentedToggle";
 import { LoadingState, StateMessage } from "../../components/ui/QueryState";
 import VideoCard, { VideoHoverActions } from "../../features/video/VideoCard";
 import { useVideoActions } from "../../features/video/useVideoActions";
+import { writeVideoState, writeWatchLater } from "../../features/video/videoWrites";
 import { usePlexCardActions } from "../../features/plexCards/usePlexCardActions";
 import { PlexHoverBar, PlexPosterCard } from "../../features/plexCards/plexCards";
 import { usePlaylistsActions } from "../playlists";
@@ -837,11 +837,8 @@ export default function Home() {
       // A full refetch, unlike the feed's stale-mark: these rails are two dozen rows, and marking
       // something watched genuinely changes what the page should answer (it can retire the hero).
       // The feed avoids this because it would refetch ten infinite-query pages per click.
-      void api
-        .setState(id, status)
+      void writeVideoState(qc, id, status)
         .then(() => {
-          // The player's related lists are never refetched: the mark goes into them.
-          patchRelated(qc, id, { status });
           return qc.invalidateQueries({ queryKey: qk.discover() });
         })
         // Without this the rejection escapes unhandled and the click just does nothing — the
@@ -858,7 +855,7 @@ export default function Home() {
 
   const onToggleSave = useCallback(
     (id: string, saved: boolean) => {
-      void (saved ? api.watchLaterAdd(id) : api.watchLaterRemove(id))
+      void writeWatchLater(qc, id, saved)
         .then(() => {
           qc.invalidateQueries({ queryKey: qk.playlists() });
           qc.invalidateQueries({ queryKey: qk.playlist() });

frontend/src/modules/notifications/NotificationsPanel.tsx

@@ -48,6 +48,7 @@ import { PageToolbar } from "../../components/ui/PageShell";
 import { PageMenu } from "../../components/ui/PageMenu";
 import { LoadingState, StateMessage } from "../../components/ui/QueryState";
 import { useNavigationActions } from "../../features/navigation/navigationContext";
+import { writeVideoState } from "../../features/video/videoWrites";
 import { useFilesActions } from "../files";
 import { useChannelsActions } from "../channels";
 import { useFeedFilters, useFeedFiltersActions } from "../feed";
@@ -170,8 +171,7 @@ export default function NotificationsPanel() {
     setPage("feed");
   }
   function revertState(meta: VideoHiddenMeta | VideoWatchedMeta) {
-    api
-      .setState(meta.videoId, "new")
+    writeVideoState(qc, meta.videoId, "new")
       .then(() => {
         qc.invalidateQueries({ queryKey: qk.feed() });
         qc.invalidateQueries({ queryKey: qk.feedSummary() });

frontend/src/modules/playlists/Playlists.tsx

@@ -3,7 +3,7 @@ import { useLatest, useStableCallback } from "../../lib/useLatest";
 import { useTranslation } from "react-i18next";
 import { useQuery, useQueryClient } from "@tanstack/react-query";
 import { qk } from "../../lib/queryKeys";
-import { patchRelated } from "../../lib/progressCache";
+import { writeVideoState } from "../../features/video/videoWrites";
 import {
   DndContext,
   KeyboardSensor,
@@ -611,16 +611,13 @@ function PlaylistDetail() {
   }
 
   function playerState(id: string, status: VideoStatus) {
-    api
-      .setState(id, status)
+    writeVideoState(qc, id, status)
       .then(() => {
         // Every cached list, not `qk.playlist(selectedId)`: the player may have been launched from a
         // list that is no longer the selected one (see `playing`), and that list holds the row whose
         // status just changed. Only lists actually on screen refetch.
         qc.invalidateQueries({ queryKey: qk.playlist() });
         qc.invalidateQueries({ queryKey: qk.feed() });
-        // The player's related lists are never refetched: the mark goes into them.
-        patchRelated(qc, id, { status });
       })
       // No catch used to mean an unhandled rejection and nothing said.
       .catch((e: unknown) => notifyActionError(e, t("errors.writeFailed.videoState")));