fix(ui): VK-iOS shows the pack CTA disabled with a toast, not a failed buy

Money purchases are not permitted in the VK iOS app (Apple ToS), and the backend
already refuses them (the CreateOrder VK-iOS freeze). Show the pack "Buy" muted
there and explain on tap ("purchases are not available on this platform"),
instead of letting the tap hit a 403 and a generic error toast. The storefront
still lists the packs.

ui/src/lib/i18n/en.ts

@@ -243,6 +243,7 @@ export const en = {
   'wallet.empty': 'The store is empty for now',
   'wallet.buy': 'Buy',
   'wallet.offer': 'Public offer',
+  'wallet.platformNoBuy': 'Purchases are not available on this platform',
   'wallet.gpStub': 'To buy chips, install the RuStore build.',
   'wallet.cur.RUB': '₽',
   'wallet.cur.VOTE': 'votes',

ui/src/lib/i18n/ru.ts

@@ -243,6 +243,7 @@ export const ru: Record<MessageKey, string> = {
   'wallet.empty': 'Магазин пока пуст',
   'wallet.buy': 'Купить',
   'wallet.offer': 'Публичная оферта',
+  'wallet.platformNoBuy': 'На данной платформе покупки невозможны',
   'wallet.gpStub': 'Чтобы покупать фишки, установите версию из RuStore.',
   'wallet.cur.RUB': '₽',
   'wallet.cur.VOTE': 'голосов',

ui/src/screens/Wallet.svelte

@@ -1,8 +1,9 @@
 <script lang="ts">
   import { onMount } from 'svelte';
   import Modal from '../components/Modal.svelte';
-  import { app, handleError } from '../lib/app.svelte';
+  import { app, handleError, showToast } from '../lib/app.svelte';
   import { gateway } from '../lib/gateway';
+  import { platformSubtype } 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';
@@ -25,6 +26,9 @@
 
   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.
+  const purchaseBlocked = context === 'vk' && platformSubtype() === 'ios';
 
   const values = $derived(catalog?.products.filter((p) => p.kind === 'value') ?? []);
   const packs = $derived(catalog?.products.filter((p) => p.kind === 'pack') ?? []);
@@ -162,7 +166,16 @@
         <div class="row product" data-testid="product" data-kind="pack" data-pid={p.productId}>
           <span class="name">{p.title}</span>
           <span class="price">{formatAmount(p.moneyAmount, p.moneyCurrency)}&nbsp;{currencyLabel(p.moneyCurrency)}</span>
-          <button class="buy" data-testid="buy-pack" disabled={busy} onclick={() => onOrder(p)}>{t('wallet.buy')}</button>
+          <button
+            class="buy"
+            class:blocked={purchaseBlocked}
+            data-testid="buy-pack"
+            disabled={busy}
+            onclick={() => {
+              if (purchaseBlocked) showToast(t('wallet.platformNoBuy'));
+              else void onOrder(p);
+            }}>{t('wallet.buy')}</button
+          >
         </div>
       {/each}
       {#if packs.length > 0}
@@ -244,6 +257,9 @@
     opacity: 0.5;
     cursor: default;
   }
+  .buy.blocked {
+    opacity: 0.5;
+  }
   .empty,
   .stub {
     margin: 0;