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/Home.tsx

@@ -18,6 +18,7 @@ import {
   type DiscoverBudget,
   type DiscoverCard,
   type DiscoverPayload,
+  HERO_TIERS,
   type HeroTier,
   type PlexCard,
   type Video,
@@ -350,7 +351,14 @@ function Hero({
           </Button>
         </div>
       </div>
-      <ComfortPinMenu menu={pinMenu} target={pinTargetForCard} title={(c) => c.title} />
+      {/* A comfort hero acts on the pin it came from: a pinned show's next episode is not itself
+          pinned, and looking the episode up offered "Pin" under "From your shelf" — a second pin.
+          The owner's call (2026-09-19): the row unpins the show. */}
+      <ComfortPinMenu
+        menu={pinMenu}
+        target={(c) => pinTargetForCard(c.pinned_from ?? c)}
+        title={(c) => (c.pinned_from ?? c).title}
+      />
     </section>
   );
 }
@@ -654,28 +662,40 @@ export default function Home() {
     [budget, qc, t],
   );
 
-  const reroll = useCallback(() => {
-    // Remember what is on screen so the next pick cannot be the same card, then take a fresh seed —
-    // never 0 (which means "the hero the page loaded with") and never the current one (a cache hit
-    // would look like a dead button).
-    if (heroKey)
-      setSeen((prev) => [...prev.filter((k) => k !== heroKey), heroKey].slice(-SEEN_WINDOW));
-    setPress((n) => n + 1);
-    setSeed((prev) => {
-      let next = prev;
-      while (next === prev || next === 0) next = Math.floor(Math.random() * 1_000_000) + 1;
-      return next;
-    });
-  }, [heroKey]);
+  const reroll = useCallback(
+    (lead?: HeroTier) => {
+      // Remember what is on screen so the next pick cannot be the same card, then take a fresh seed —
+      // never 0 (which means "the hero the page loaded with") and never the current one (a cache hit
+      // would look like a dead button).
+      if (heroKey)
+        setSeen((prev) => [...prev.filter((k) => k !== heroKey), heroKey].slice(-SEEN_WINDOW));
+      // `lead` asks for a tier: the next press whose rotation leads with it. The rotation carries on
+      // from there, so the button's following press is the tier after it, as it would have been.
+      setPress((n) => {
+        let next = n + 1;
+        // Guarded on membership: a click handler passed straight in would hand over its event
+        // as `lead`, and this loop would never end.
+        if (lead && HERO_TIERS.includes(lead))
+          while (HERO_TIERS[next % HERO_TIERS.length] !== lead) next += 1;
+        return next;
+      });
+      setSeed((prev) => {
+        let next = prev;
+        while (next === prev || next === 0) next = Math.floor(Math.random() * 1_000_000) + 1;
+        return next;
+      });
+    },
+    [heroKey],
+  );
 
   // "Meglepetés" from the command palette: the request is made on another page, so it waits as a
   // token until this module's chunk has actually mounted (see lib/homeIntent). The subscribed value
   // is what WAKES this effect; `takeSurprise()` is what decides — it clears the token and answers
   // false to every later pass, including StrictMode's second mount invocation and the re-runs
-  // `reroll`'s changing identity causes.
+  // `reroll`'s changing identity causes — and to a token minted for another history entry.
   const surpriseRequest = useSurpriseRequest();
   useEffect(() => {
-    if (surpriseRequest && takeSurprise()) reroll();
+    if (surpriseRequest !== null && takeSurprise()) reroll("surprise");
   }, [surpriseRequest, reroll]);
 
   if (q.isPending) return <LoadingState />;
@@ -716,7 +736,7 @@ export default function Home() {
           tier={hero.tier}
           card={hero.card}
           onPlay={onPlay}
-          onReroll={reroll}
+          onReroll={() => reroll()}
           rerolling={rerolling}
         />
       ) : (
@@ -743,7 +763,7 @@ export default function Home() {
                 type="button"
                 icon={<RotateCcw className="h-4 w-4" />}
                 loading={rerolling}
-                onClick={reroll}
+                onClick={() => reroll()}
               >
                 {t("home.hero.reroll")}
               </Button>