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/DrawPublishService.php

@@ -79,10 +79,7 @@ final class DrawPublishService
 
     private function applyPublishedToDraw(Draw $draw, DrawResultBatch $batch): Draw
     {
-        $cooldownMinutes = max(0, (int) LotterySettings::get(
-            'draw.cooldown_minutes',
-            (int) config('lottery.draw.cooldown_minutes', 15),
-        ));
+        $cooldownMinutes = LotterySettings::drawCooldownMinutes();
         if ($cooldownMinutes > 0) {
             $draw->forceFill([
                 'status' => DrawStatus::Cooldown->value,