feat: Raise meaningful exception when oauth callback times out

[chalmerlowe]

This PR addresses the issue where a timeout in run_local_server caused an AttributeError. It introduces a WSGITimeout exception that is raised when the server times out waiting for a callback. A regression test has been added to tests/unit/test_flow.py.

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PR created automatically by Jules for task 14978887234858898738 started by @chalmerlowe

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[gemini-code-assist]

Summary of Changes

Hello @chalmerlowe, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request refines the error handling within the OAuth callback process by introducing a dedicated WSGITimeout exception. This change ensures that when the local server fails to receive an authorization response within the specified timeout period, a more descriptive and actionable error is raised, improving the reliability and debuggability of the authentication flow.

Highlights

• New Exception Type: Introduced a new WSGITimeout exception to specifically handle timeout scenarios when the local server is waiting for an OAuth callback, replacing a generic AttributeError.
• Improved Error Handling: Modified the run_local_server function to explicitly check for a timeout condition and raise the WSGITimeout exception, providing clearer error diagnostics.
• Documentation Update: Updated the docstring for run_local_server to reflect the new WSGITimeout exception that can be raised.
• Regression Test: Added a new unit test, test_run_local_server_timeout, to ensure that the WSGITimeout exception is correctly raised when the server times out.

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[gemini-code-assist]

Code Review

This pull request introduces a WSGITimeout exception to provide a more meaningful error when the local server for the OAuth flow times out waiting for the callback. This is a good improvement over the previous behavior which resulted in an AttributeError. The changes include the new exception class, updated docstrings, and the logic to raise the exception on timeout. A new unit test has been added to cover this timeout scenario. The implementation is solid, and I have one suggestion to make the new test more robust.

[gemini-code-assist]

This test correctly verifies that a WSGITimeout is raised. To make it more robust, you could also assert that webbrowser.open() was called, as this happens before the server waits for the request and times out. This would ensure that part of the flow is also behaving as expected in the timeout scenario, consistent with other tests for run_local_server.

Suggested change

	with pytest.raises(flow.WSGITimeout):
	instance.run_local_server(timeout_seconds=1)
	with pytest.raises(flow.WSGITimeout):
	instance.run_local_server(timeout_seconds=1)
	webbrowser_mock.get.assert_called_with(None)
	webbrowser_mock.get.return_value.open.assert_called_once()