audit support of evaluate or program.execute method(Support for execution tracing and variable-level audit logs)

从 evaluate 和 program.execute 入口开始，检查诸如 .exists() 之类的集合宏如何处理其元素。定义 trace 或 audit-log API，包括匹配的值、索引、表达式片段和失败说明，然后添加覆盖测试，证明请求的结果和 trace 会一起返回。

Currently, the common-expression-language library evaluates expressions but provides limited or no visibility into the evaluation process. Specifically, there is:

No built-in execution trace.
No automatic "why it failed" explanation for complex logic.
No variable-level audit log to identify which specific part of the context triggered a result.

When dealing with collection-based macros like .exists(), etc,. it is difficult to debug which specific element in a list caused the expression to return True or False.

I would like a mechanism that returns a trace or an audit log. This trace should identify which value in the context resulted in the final pass, fail, or result.

Additional context (Example)
Consider the following scenario:

Expression: value.exists(v, v.x == 5)
Context: {"value": [{"x": 7}, {"x": 15}, {"x": 5}]}

The Issue:
The library correctly returns True because the third element matches the condition. However, there is no built-in way to programmatically identify that {"x": 5} was the specific element that satisfied the condition. In more complex real-world scenarios, knowing "why" or "which" value triggered the result is critical for auditing and debugging.

Suggested Output/API:
It would be helpful if the library could provide an output similar to:

{
"result": true,
"trace": {
"matched_element": {"x": 5},
"index": 2,
"expression_part": "v.x == 5"
}
}

Thanks in advance, please let me know if any more information or details needed.