Reduce Transfer storage price to GHS 0.15 per GB per month.

Updates config default, env examples, and removes hardcoded GHS 1.00 copy on the dashboard.

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

app/Http/Controllers/Transfer/FilesController.php

@@ -31,7 +31,7 @@ class FilesController extends Controller
             'files' => $files,
             'storageBytes' => (int) $storageBytes,
             'storageGb' => round($storageBytes / (1024 * 1024 * 1024), 2),
-            'pricePerGb' => (float) config('transfer.price_per_gb_month', 1.0),
+            'pricePerGb' => (float) config('transfer.price_per_gb_month', 0.15),
         ]);
     }
 }