More gracefully fail on `pyproject.toml` error

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.

```

Start with the "create environment..." flow and the logged `uv pip install --python ... -e ...` invocation, using the malformed `pyproject.toml` example to reproduce the failure. Done means the flow reports the package metadata error more clearly or exits gracefully instead of exposing the raw failure.

Written by the indexing model from the issue text.