refactor(context): 重命名上下文构建器及更新相关方法命名

- 将 ProcessContext 中的 builder() 重命名为 createModifyBuilder() 并添加调用栈日志
- ProcessContextBuilder 中所有 with* 方法统一改为 set* 命名风格
- Flow 各节点及流程处理器中调用 builder() 替换为 createModifyBuilder()
- 虚拟测试环境相关 ContextBuilder 中方法同步改名保持一致
- 优化流程节点中上下文修改代码调用，提升代码规范性
- 添加Config中加载自定义流程配置的占位注释及代码
- 无功能改动，纯代码风格及命名规范调整

app/flow/strategies/TimeValidationStrategy.php

@@ -79,7 +79,7 @@ class TimeValidationStrategy extends AbstractStrategy
             // 从数据库按流程类型精确查询
             $requiredDuration = $this->getDurationFromDb($stepCode, $processType);
             if ($requiredDuration > 0) {
-                $context = $context->builder()->withStepDuration($stepCode, $requiredDuration)->build();
+                $context = $context->createModifyBuilder()->setStepDuration($stepCode, $requiredDuration)->build();
             } else {
                 // 最后使用上下文已缓存值
                 $requiredDuration = $context->getStepDuration($stepCode);
@@ -106,7 +106,7 @@ class TimeValidationStrategy extends AbstractStrategy
                 $voice = VoiceMessage::NOT_ENOUGH_TIME->value;
                 $voice = str_replace('{step}', $stepCode, $voice);
                 $voice = str_replace('{time}', $requiredDuration - $duration, $voice);
-                $context = $context->builder()->customError($voice)->build();
+                $context = $context->createModifyBuilder()->setCustomError($voice)->build();
             }
             return $context;
         }