feat(admin): 密码校验统一与后台 API/设置增强

- 管理端账号/代理/站点等密码最短长度统一为 6 位
- LotterySettings、审计日志展示、币种与报表接口等小修复
- 补充设置批量更新、注单、校验错误等相关测试

app/Http/Requests/Admin/Concerns/AdminAccountFieldRules.php

@@ -13,7 +13,7 @@ trait AdminAccountFieldRules
     }
 
     /** @return array<int, mixed> */
-    protected function adminLoginPasswordRules(bool $required = true, int $min = 8, int $max = 256): array
+    protected function adminLoginPasswordRules(bool $required = true, int $min = 6, int $max = 256): array
     {
         $rules = ['string', 'min:'.$min, 'max:'.$max];