fix(e24): the review's seven frontend defects on the Home surface

Shift+W was dead whenever anything was open. The global handler called `setPage` directly,
so the page change unmounted the player (it lives inside the module column) and that
unmount's reconcile reclaimed the entry the navigation had just pushed — the player closed
and the page snapped back. `closeThenNavigate` cannot serve here: a global key does not
know which overlay is open, or whether one is. `navigateOverOverlays` is the same fix one
step shorter — bury the live overlay entries first, so the unmount consumes the marks
instead of issuing `history.back()`.

`q.isError` had no `&& !data` guard, alone among 33 call sites and against the convention
`ui/QueryState` documents: react-query flips status to error on a failed REFETCH while
keeping the payload, and every mutation here invalidates the discover prefix, so one blip
while marking a card watched blanked a fully populated landing page.

The reroll's key rooted at "discover-pick", outside the prefix every mutation invalidates,
so a rerolled hero outlived the page: play it, finish it, and it was still the answer with
a zeroed progress bar. It now sits under the same root. A FAILED reroll also rewound the
hero to the card the page loaded with, several presses back, because a new key per press
means `keepPreviousData` (pending-only) cannot cover an error; the last resolved pick is
held instead.

The bookmark on a rail tile never updated — `VideoCard` reads `video.saved` from this
payload and keeps no optimistic state — so the star stayed empty and the next click
re-sent the same call.

The shelf reorder wrote a captured snapshot back on failure rather than re-asking the
server, which its own comment promised: two overlapping moves each reverted to their own
snapshot and settled on an order neither side held, and since `before` is the whole
payload a rollback also discarded any rail refresh that had landed meanwhile. It now
invalidates the discover PREFIX on settle, which also fixes the sibling budgets keeping
the pre-move order.

The hero/rail de-duplication matched one key, so for a Plex series — the rail row is the
show, the hero is the episode it resolves to — the same series printed twice; it now
matches both keys, as `hero.pick`'s own exclusion already did. And when the hero empties
the resume rail, the rail is hidden rather than announcing "nothing half-finished right
now" under a hero captioned "where you left off".

Ten regression tests, all mutation-checked. Three of them were rewritten after the first
mutation round showed they could not go red: two asserted before the state under test had
settled, one matched a title the Plex tile does not render.

frontend/src/lib/queryKeys.ts

@@ -102,9 +102,12 @@ export const qk = {
   // anyway. Single-id plex keys stay precisely typed.
   // The Home surface (E24). `discover()` with no args is the prefix every mutation invalidates —
   // pinning something changes the shelf AND can change the hero, so the two are never invalidated
-  // separately. The reroll has its own key so pressing "Mást kérek" does not refetch the rails.
+  // separately. The reroll has its own key so pressing "Mást kérek" does not refetch the rails —
+  // but it sits UNDER the same root, because a sibling root ("discover-pick") is not matched by
+  // that prefix and the rerolled hero silently outlived every invalidation on the page: play it,
+  // finish it, and it was still the answer on screen with a zeroed progress bar.
   discover: (...rest: unknown[]) => ["discover", ...rest],
-  discoverPick: (...rest: unknown[]) => ["discover-pick", ...rest],
+  discoverPick: (...rest: unknown[]) => ["discover", "pick", ...rest],
   comfortPins: () => ["comfort-pins"] as const,
   plex: () => ["plex"] as const,
   plexWatchLink: () => ["plex-watch-link"] as const,