refactor: 迁移彩票设置至 LotterySettings 服务

- 更新多个控制器和服务，使用 LotterySettings 服务获取彩票相关配置，如默认币种、开奖间隔、下注窗口等，提升代码一致性与可维护性。
- 移除 .env.example 中不再使用的配置项，建议通过后台管理进行设置。

app/Services/Draw/DrawHallSnapshotBuilder.php

@@ -10,6 +10,7 @@ use App\Models\DrawResultItem;
 use App\Models\DrawResultBatch;
 use App\Lottery\DrawResultBatchStatus;
 use App\Services\Jackpot\JackpotSummaryService;
+use App\Services\LotterySettings;
 
 /**
  * `GET draw/current` 与大厅 WS 快照共用数据结构。
@@ -237,7 +238,7 @@ final class DrawHallSnapshotBuilder
 
         $effectiveStatus = $this->effectiveHallDisplayStatus($target, $nowUtc);
 
-        $scheduleTz = (string) config('lottery.draw.timezone', 'UTC');
+        $scheduleTz = LotterySettings::drawTimezone();
 
         $payload = [
             'schedule_timezone' => $scheduleTz,
@@ -324,6 +325,6 @@ final class DrawHallSnapshotBuilder
             return $code;
         }
 
-        return strtoupper(substr(trim((string) config('lottery.default_currency', 'NPR')), 0, 16));
+        return LotterySettings::defaultCurrency();
     }
 }