Point in-app wallet top-up at the billing API (key the app already holds)

qr-plus authenticates to the monolith with a billing service key, not an
identity key, so the modal's top-up now goes through BillingClient::topup ->
POST /api/billing/topup. Drops the unused IdentityClient::walletTopup.

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

app/Http/Controllers/WalletTopupController.php

@@ -2,7 +2,7 @@
 
 namespace App\Http\Controllers;
 
-use App\Services\Identity\IdentityClient;
+use App\Services\Billing\BillingClient;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Http\RedirectResponse;
 use Illuminate\Http\Request;
@@ -15,7 +15,7 @@ use Illuminate\Http\Request;
  */
 class WalletTopupController extends Controller
 {
-    public function store(Request $request, IdentityClient $identity): JsonResponse|RedirectResponse
+    public function store(Request $request, BillingClient $billing): JsonResponse|RedirectResponse
     {
         $validated = $request->validate([
             'amount' => ['required', 'numeric', 'min:5', 'max:5000'],
@@ -25,7 +25,7 @@ class WalletTopupController extends Controller
         $returnUrl = $validated['return_url'] ?? (string) (url()->previous() ?: url('/'));
 
         try {
-            $checkoutUrl = $identity->walletTopup(
+            $checkoutUrl = $billing->topup(
                 (string) $request->user()->public_id,
                 (float) $validated['amount'],
                 $returnUrl,

app/Services/Billing/BillingClient.php

@@ -35,6 +35,22 @@ class BillingClient
         return (int) ($this->get('/balance', ['user' => $publicId])['balance_minor'] ?? 0);
     }
 
+    /**
+     * Start a Paystack checkout to top up the central wallet; returns the
+     * checkout URL. Backs the in-app two-step "Add funds" modal.
+     */
+    public function topup(string $publicId, float $amount, string $returnUrl): string
+    {
+        $res = Http::withToken($this->token())->acceptJson()->timeout(15)->post($this->base().'/topup', [
+            'user' => $publicId,
+            'amount' => $amount,
+            'return_url' => $returnUrl,
+        ]);
+        $res->throw();
+
+        return (string) ($res->json()['checkout_url'] ?? '');
+    }
+
     public function canAfford(string $publicId, int $amountMinor): bool
     {
         return (bool) ($this->get('/can-afford', ['user' => $publicId, 'amount_minor' => $amountMinor])['affordable'] ?? false);

app/Services/Identity/IdentityClient.php

@@ -43,24 +43,6 @@ class IdentityClient
         return (array) $response->json('data', []);
     }
 
-    /**
-     * Start a central-wallet Paystack top-up for an account and return the
-     * Paystack checkout URL. Backs the in-app "Add funds" modal so users top up
-     * without leaving the app for the central wallet page.
-     */
-    public function walletTopup(string $publicId, float $amount, string $returnUrl): string
-    {
-        $response = $this->request()->post($this->url('/identity/wallet-topup-account'), [
-            'user' => $publicId,
-            'amount' => $amount,
-            'return_url' => $returnUrl,
-        ]);
-
-        $response->throw();
-
-        return (string) $response->json('data.checkout_url', '');
-    }
-
     private function request()
     {
         return Http::withToken((string) config('identity.api_key'))