follow-up: harden Unix socket test against AF_UNIX path limits

[gaoguobin]

Motivation

• Prevent flaky AF_UNIX path too long failures on Linux/macOS CI caused by long temporary directories so the test exercises backup behavior reliably.
• Keep coverage of Unix-socket skipping logic while removing environment-dependent setup failures.

Description

• Modify test_backup_skips_venv_symlinks_and_unix_sockets to create a short temporary symlink target and bind the Unix socket through that short path when possible.
• Add a length guard (len(str(bind_path)) < 100) to only attempt AF_UNIX bind when the computed path is short enough.
• Ensure socket parent directory creation uses exist_ok=True and close the test server promptly after bind attempts.

Testing

• Ran python -m unittest tests.test_core.CodexEnvironmentBackupTests.test_backup_skips_venv_symlinks_and_unix_sockets and it passed (OK).

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Codex Task

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Restore Windows-safe handling for AF_UNIX bind failures

This server.bind(...) call is now unguarded, so on Windows environments where socket.AF_UNIX exists but binding fails (for example due to platform/socket-path constraints), the test raises OSError and fails instead of continuing without a created socket. The previous version explicitly swallowed bind errors on os.name == "nt", so this change reintroduces platform-specific CI failures for test_backup_skips_venv_symlinks_and_unix_sockets rather than just skipping the socket assertion path.

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