feat(billing): Google Play build shows "not implemented" for coin buys

Add a gated `googleplay` store flavor (NEXT_PUBLIC_STORE=googleplay) so the
appeal/Play build ships a payment-free coin shop. isPurchaseDisabled() makes
BuyCoinsScreen short-circuit to a "not implemented" notice instead of starting
ZarinPal or Iranian IAB (both rejected on Play). Default web/Bazaar/Myket
builds are unaffected. New i18n key buy.notImplemented (fa+en).

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 { consumeStorePurchase, isStoreBilling, purchaseViaStore } from "@/lib/storeBilling";
+import { consumeStorePurchase, isPurchaseDisabled, isStoreBilling, purchaseViaStore } from "@/lib/storeBilling";
 import { sound } from "@/lib/sound";
 import { CoinPack } from "@/lib/online/types";
 import { cn } from "@/lib/cn";
@@ -39,6 +39,14 @@ export function BuyCoinsScreen() {
     setBusy(p.id);
     setMsg("");
 
+    // Google Play build: coin purchases are intentionally not wired (no Iranian
+    // IAB on Play). Show a notice instead of starting any payment flow.
+    if (isPurchaseDisabled()) {
+      setMsg(t("buy.notImplemented"));
+      setBusy(null);
+      return;
+    }
+
     // Inside a store build (Cafe Bazaar / Myket), route through store billing.
     if (isStoreBilling()) {
       try {

src/lib/i18n.tsx

@@ -139,6 +139,7 @@ const fa: Dict = {
   "buy.bonus": "هدیه",
   "buy.redirecting": "صفحهٔ پرداخت در تب جدید باز شد. پس از پرداخت، سکه‌ها به‌صورت خودکار اضافه می‌شوند.",
   "buy.failed": "پرداخت در دسترس نیست. بعداً دوباره تلاش کنید.",
+  "buy.notImplemented": "پیاده‌سازی نشده است.",
   "buy.popular": "محبوب",
   "buy.best": "بهترین",
   "buy.starter": "شروع",
@@ -528,6 +529,7 @@ const en: Dict = {
   "buy.bonus": "bonus",
   "buy.redirecting": "Payment opened in a new tab. Your coins will be added automatically once you pay.",
   "buy.failed": "Payment unavailable. Please try again later.",
+  "buy.notImplemented": "Not implemented.",
   "buy.popular": "Popular",
   "buy.best": "Best value",
   "buy.starter": "Starter",

src/lib/storeBilling.ts

@@ -14,7 +14,7 @@
 import { registerPlugin } from "@capacitor/core";
 import { CoinPack } from "./online/types";
 
-export type StoreId = "bazaar" | "myket" | "web";
+export type StoreId = "bazaar" | "myket" | "web" | "googleplay";
 
 const ENV_STORE = ((process.env.NEXT_PUBLIC_STORE as StoreId | undefined) ?? "web");
 const PACKAGE = process.env.NEXT_PUBLIC_APP_PACKAGE ?? "com.bargevasat.app";
@@ -54,7 +54,18 @@ export function getStore(): StoreId {
 
 /** True when coin purchases should go through a store (not the web ZarinPal gateway). */
 export function isStoreBilling(): boolean {
-  return getStore() !== "web";
+  const s = getStore();
+  return s !== "web" && s !== "googleplay";
+}
+
+/**
+ * True for the Google Play build, where real-money coin purchases are NOT wired
+ * (no Iranian IAB on Play, and we don't ship a Play billing path). The Buy-Coins
+ * screen shows a "not implemented" notice instead of starting a purchase. Set via
+ * the build flavor `NEXT_PUBLIC_STORE=googleplay`.
+ */
+export function isPurchaseDisabled(): boolean {
+  return getStore() === "googleplay";
 }
 
 function skuFor(pack: CoinPack): string {