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/AdminUserStoreRequest.php

@@ -50,7 +50,7 @@ final class AdminUserStoreRequest extends ApiFormRequest
             'username' => ['required', 'string', 'min:2', 'max:64', 'regex:/^[a-zA-Z0-9._-]+$/u', 'unique:admin_users,username'],
             'nickname' => ['required', 'string', 'max:128'],
             'email' => ['nullable', 'string', 'email', 'max:255'],
-            'password' => ['required', 'string', 'min:8', 'max:256'],
+            'password' => ['required', 'string', 'min:6', 'max:256'],
             'status' => ['sometimes', 'integer', 'in:0,1'],
             'admin_site_id' => ['required', 'integer', 'exists:admin_sites,id'],
             'role_slugs' => ['required', 'array', 'min:1'],