The documented import for `assert_output_satisfies` raises `ImportError`

## Bug Description

The import shown in `semantic.py`'s own module docstring fails.

## Root Cause

`src/conductor/ai/agents/testing/semantic.py:9` documents
`from conductor.ai.agents.testing import assert_output_satisfies`, but `testing/__init__.py`
never imports `semantic` and the name is absent from `__all__` (`__init__.py:61-97`).

## Steps to Reproduce

```
python -c "from conductor.ai.agents.testing import assert_output_satisfies"
# ImportError
```

## Expected Behavior

Either add the re-export or correct the docstring. The re-export looks like the intent, since
every other assertion in the package is exposed that way. Working import today is
`from conductor.ai.agents.testing.semantic import assert_output_satisfies`.

## Additional Notes

Verified against `origin/main` @ `c99e2cf9`. Found while reading the module; unrelated to the
tool-call and event defects filed separately.

从 src/conductor/ai/agents/testing/semantic.py 和 src/conductor/ai/agents/testing/__init__.py 开始，重点查看文档中的 import 以及第 61-97 行的 __all__ 部分。使用 issue 中的 Python 命令复现失败，然后通过 testing 包的相关检查验证所选的文档或导出行为。当文档中的 import 与受支持的公共 API 保持一致时，即表示完成。

由索引模型根据 Issue 内容生成。