Add chunked uploads and raise storage rate to GHS 0.30/GB/month.

Large files upload in 5 MB chunks (hosting file manager pattern) for the
transfer UI and Ladill Mail S2S API, with no app-level file size cap when
TRANSFER_MAX_FILE_BYTES=0.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/Http/Controllers/Qr/AccountController.php

@@ -61,7 +61,7 @@ class AccountController extends Controller
 
         $storageBytes = (int) $activeTransfers->sum('storage_bytes');
         $storageGb = round($storageBytes / (1024 * 1024 * 1024), 2);
-        $pricePerGb = (float) config('transfer.price_per_gb_month', 0.15);
+        $pricePerGb = (float) config('transfer.price_per_gb_month', 0.30);
         $monthlyTotalGhs = round($activeTransfers->sum(fn (Transfer $transfer) => $transfer->monthlyCostGhs()), 2);
 
         return view('qr.account.billing', [