fix(home): shelf honours the Plex gate; hero unpins its origin; palette asks for a surprise

- A13: with Plex off, the Home shelf and the hero's comfort tier go YouTube-only like the rails
  beside them (owner's call: hide the tiles). The pins are kept; GET /pins still lists them.
- Reorder deals the listed pins into the slots they already hold, so a partial list (hidden Plex
  pins, a stale tab) no longer puts two pins on one position; repeats are ignored.
- A21: a comfort hero carries `pinned_from`, the shelf entry it was resolved from; its menu acts on
  that pin, so a pinned show's next episode offers "Unpin" instead of creating a second pin.
- B12: the palette's "Meglepetés" asks for the surprise tier (the next press leading with it); the
  rotation carries on from there.
- B13: the surprise token names the history entry it was requested for (minted by setPage's new
  `then`, after the push) and is dropped on any other entry, so a navigation that never mounted
  Home cannot replay it later.

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

@@ -156,6 +156,23 @@ describe("NavigationProvider · never under an open overlay", () => {
     expect(window.history.state).toMatchObject({ sfPage: "plex" });
   });
 
+  // `then` belongs to the NEW entry (the palette's "Meglepetés" token names it — lib/homeIntent), so
+  // over an open player it must wait for the push, and with nothing to push it still runs.
+  it("runs setPage's `then` after the push, on the entry the push made", async () => {
+    const { result } = render();
+    await openOverlay();
+    const seen: unknown[] = [];
+    expect(result.current.page).not.toBe("plex");
+    act(() => result.current.setPage("plex", () => seen.push(window.history.state?.sfPage)));
+    expect(seen).toEqual([]);
+    await settle();
+    await settle();
+    expect(seen).toEqual(["plex"]);
+
+    act(() => result.current.setPage("plex", () => seen.push("again")));
+    expect(seen).toEqual(["plex", "again"]);
+  });
+
   // Shift+W on Home with the player open (owner decision 2026-09-09): nothing to push, but the player
   // closes, and its entry is reclaimed rather than orphaned under a push that never happened.
   it("setPage to the current page closes the overlay and pushes nothing", async () => {