More gracefully fail on `pyproject.toml` error

還沒有人認領這個 Issue。

tried going through the "create environment..." flow with a `pyproject.toml` file but I had an error since my `pyproject.toml` file was incorrectly formatted. Would be good if the error message was better or it failed more gracefully

```
Resolved Python Environment /Users/eleanorboyd/python-envs-scenarios/existing-env-folder/.venv/bin/python
2025-05-14 09:19:39.308 [info] Running: uv pip install --python /Users/eleanorboyd/python-envs-scenarios/existing-env-folder/.venv/bin/python -e /Users/eleanorboyd/python-envs-scenarios/existing-env-folder
2025-05-14 09:19:39.378 [info] error: Failed to extract static metadata from `pyproject.toml`
Caused by: TOML parse error at line 6, column 8
|
6 | name = "existing env folder"
| ^^^^^^^^^^^^^^^^^^^^^
Not a valid package or extra name: "existing env folder". Names must start and end with a letter or digit and may only contain -, _, ., and alphanumeric characters.

```

從「create environment...」流程以及記錄中的 `uv pip install --python ... -e ...` 呼叫開始，使用格式錯誤的 `pyproject.toml` 範例來重現失敗。完成的標準是：該流程能更清楚地回報套件中繼資料錯誤，或正常結束，而不是暴露原始失敗資訊。

由索引模型根據 Issue 內容生成。