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

tests/Unit/ApiValidationErrorsTest.php

@@ -47,11 +47,11 @@ test('keeps already localized chinese messages', function (): void {
 
 test('normalizes english min length for password in zh', function (): void {
     $errors = ApiValidationErrors::normalize(
-        ['password' => ['The password field must be at least 8 characters.']],
+        ['password' => ['The password field must be at least 6 characters.']],
         'zh',
     );
 
-    expect($errors['password'][0])->toBe('密码至少需要 8 个字符。');
+    expect($errors['password'][0])->toBe('密码至少需要 6 个字符。');
 });
 
 test('normalizes exact draw items message in zh', function (): void {