fix(ui): correct the VK-iOS purchase block + add an iOS store note

The VK-iOS detection used platformSubtype(), which is server-derived for VK and
so never reported iOS on the client — the pack CTA stayed active and a tap hit a
403 with a generic error. Read the device family from the signed vk_platform
launch param (normalizeSubtype(vkPlatform())) instead. Under the store header on
VK-iOS, add a note that purchases are prohibited by Apple policy, linking to the
web version (opened through VK's external-link route).

ui/src/lib/i18n/en.ts

@@ -244,6 +244,9 @@ export const en = {
   'wallet.buy': 'Buy',
   'wallet.offer': 'Public offer',
   'wallet.platformNoBuy': 'Purchases are not available on this platform',
+  'wallet.iosBlockedPre': 'Purchases on iOS are prohibited by Apple policy. Try the ',
+  'wallet.iosBlockedLink': 'other version',
+  'wallet.iosBlockedPost': ' of the game.',
   'wallet.gpStub': 'To buy chips, install the RuStore build.',
   'wallet.cur.RUB': '₽',
   'wallet.cur.VOTE': 'votes',

ui/src/lib/i18n/ru.ts

@@ -244,6 +244,9 @@ export const ru: Record<MessageKey, string> = {
   'wallet.buy': 'Купить',
   'wallet.offer': 'Публичная оферта',
   'wallet.platformNoBuy': 'На данной платформе покупки невозможны',
+  'wallet.iosBlockedPre': 'Покупки на iOS запрещены политикой Apple. Попробуйте воспользоваться ',
+  'wallet.iosBlockedLink': 'другой версией',
+  'wallet.iosBlockedPost': ' игры.',
   'wallet.gpStub': 'Чтобы покупать фишки, установите версию из RuStore.',
   'wallet.cur.RUB': '₽',
   'wallet.cur.VOTE': 'голосов',

ui/src/screens/Wallet.svelte

@@ -3,12 +3,12 @@
   import Modal from '../components/Modal.svelte';
   import { app, handleError, showToast } from '../lib/app.svelte';
   import { gateway } from '../lib/gateway';
-  import { platformSubtype } from '../lib/platform';
+  import { normalizeSubtype } from '../lib/platform';
   import { t, i18n, type MessageKey } from '../lib/i18n/index.svelte';
   import { executionContext, formatAmount, needsWebSpendWarning, type SpendContext } from '../lib/wallet';
   import { isGooglePlayBuild } from '../lib/distribution';
-  import { openExternalUrl } from '../lib/links';
+  import { onExternalLinkClick, openExternalUrl } from '../lib/links';
-  import { vkShowOrderBox } from '../lib/vk';
+  import { vkPlatform, vkShowOrderBox } from '../lib/vk';
   import type { Wallet, Catalog, CatalogProduct } from '../lib/model';
 
   // The Wallet section: the context-visible chip balances, the active benefits, and the storefront.
@@ -27,8 +27,9 @@
   const context: SpendContext = executionContext();
   const gpBuild = isGooglePlayBuild();
   // Money purchases are not permitted inside the VK iOS app (Apple ToS); the pack CTA is shown
-  // muted and taps explain why, rather than hiding the storefront.
+  // muted and taps explain why, rather than hiding the storefront. VK's device family is not on the
-  const purchaseBlocked = context === 'vk' && platformSubtype() === 'ios';
+  // client platformSubtype (server-derived) — read it from the signed vk_platform launch param.
+  const purchaseBlocked = context === 'vk' && normalizeSubtype(vkPlatform()) === 'ios';
 
   const values = $derived(catalog?.products.filter((p) => p.kind === 'value') ?? []);
   const packs = $derived(catalog?.products.filter((p) => p.kind === 'pack') ?? []);
@@ -151,6 +152,10 @@
 
   <section>
     <h3>{t('wallet.store')}</h3>
+    {#if purchaseBlocked}
+      <!-- prettier-ignore -->
+      <p class="ios-note" data-testid="ios-note">{t('wallet.iosBlockedPre')}<a href="https://erudit-game.ru/app/" target="_blank" rel="noopener noreferrer" onclick={onExternalLinkClick}>{t('wallet.iosBlockedLink')}</a>{t('wallet.iosBlockedPost')}</p>
+    {/if}
     {#each values as p (p.productId)}
       <div class="row product" data-testid="product" data-kind="value" data-pid={p.productId}>
         <span class="name">{p.title}</span>
@@ -260,6 +265,17 @@
   .buy.blocked {
     opacity: 0.5;
   }
+  .ios-note {
+    margin: 0 0 4px;
+    padding: 8px 12px;
+    color: var(--text-muted);
+    font-size: 0.85rem;
+    border: 1px dashed var(--border);
+    border-radius: var(--radius-sm);
+  }
+  .ios-note a {
+    color: var(--accent);
+  }
   .empty,
   .stub {
     margin: 0;