feat(iap): native Myket in-app billing plugin (AIDL) + wire purchase/consume

Implements real Myket IAB for the Capacitor app (Myket has no purchase
deep-link like Bazaar — it uses the classic Google Play IAB v3 AIDL bound to
the Myket app):

- AIDL: com.android.vending.billing.IInAppBillingService (Myket-compatible).
- MyketBillingPlugin (Capacitor): binds ir.mservices.market via
  "ir.mservices.market.InAppBillingService.BIND", runs getBuyIntent →
  startIntentSenderForResult, verifies INAPP_DATA_SIGNATURE with the RSA key
  (Security.java, SHA1withRSA), returns the purchaseToken; consume() too.
- MainActivity registers the plugin + forwards the purchase activity result.
- Manifest: ir.mservices.market.BILLING permission + <queries> for Android 11+
  package visibility.
- build.gradle: enable buildFeatures.aidl (AGP 8 disables it by default).
- storeBilling: Myket goes through the plugin (RSA key embedded); after server
  verify, BuyCoins consumes the purchase so coins can be re-bought.

Bazaar (deep-link) and web (ZarinPal) paths unchanged. Needs on-device testing
with the Myket app installed + published products.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/components/screens/BuyCoinsScreen.tsx

@@ -6,7 +6,7 @@ import { ScreenHeader, ScreenShell } from "@/components/online/ScreenHeader";
 import { useSessionStore } from "@/lib/session-store";
 import { useI18n } from "@/lib/i18n";
 import { getService } from "@/lib/online/service";
-import { isStoreBilling, purchaseViaStore } from "@/lib/storeBilling";
+import { consumeStorePurchase, isStoreBilling, purchaseViaStore } from "@/lib/storeBilling";
 import { sound } from "@/lib/sound";
 import { CoinPack } from "@/lib/online/types";
 import { cn } from "@/lib/cn";
@@ -47,6 +47,8 @@ export function BuyCoinsScreen() {
         if (r.kind === "token") {
           const v = await getService().verifyIab(r.store, r.productId, r.token);
           if (v.ok && v.profile) {
+            // Consumable: let the store mark it consumed so it can be re-bought.
+            await consumeStorePurchase(r.store, r.token);
             setProfile(v.profile);
             sound.play("purchase");
             setGained(v.coins);