fix: use sudo -n for lsof retry in preflight to avoid password prompt

[cv]

Problem

The port-availability preflight check in checkPortAvailable retries with sudo lsof to detect root-owned listeners when unprivileged lsof returns empty output. Without -n (non-interactive mode), sudo blocks on a Password: prompt, stalling non-interactive installs:

• curl -fsSL https://www.nvidia.com/nemoclaw.sh | bash
• nemoclaw onboard --non-interactive
• NEMOCLAW_NON_INTERACTIVE=1
• CI pipelines

Fix

Use sudo -n so it fails immediately when passwordless sudo is unavailable, falling through to the TCP bind probe instead of hanging.

This is the only sudo call in the codebase that should degrade gracefully — the other sudo calls (swap creation) intentionally require elevated privileges to succeed.

Summary by CodeRabbit

• Bug Fixes
  • Improved preflight setup process by enabling non-interactive mode for privilege elevation checks, preventing unexpected password prompts during port availability verification.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 4e5b0d7a-5cbe-4be9-a535-3617ebc5c97e

📥 Commits

Reviewing files that changed from the base of the PR and between 39e9b1f and 5ab08f6.

📒 Files selected for processing (1)

• bin/lib/preflight.js

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📝 Walkthrough

Walkthrough

A single line modification in the port availability check function updates the sudo invocation to use non-interactive mode (-n flag) when retrying with elevated privileges after initial lsof output is empty.

Changes

Cohort / File(s)	Summary
Port Availability Check bin/lib/preflight.js	Modified checkPortAvailable to use sudo -n (non-interactive mode) instead of sudo when retrying lsof command with elevated privileges, preventing password prompts.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~5 minutes

Poem

🐰 With -n flag in hand so proud,
No passwords asked, no prompts loud,
The sudo dance runs silent, clean,
Non-interactive, smooth, serene!
A tiny tweak, but oh so keen! 🚀

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and specifically describes the main change: using sudo -n flag in the lsof retry within the preflight check to avoid password prompts.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/sudo-n-lsof-preflight

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_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[ericksoa]

No regression risk. The -n flag prevents a surprise password prompt during preflight — if sudo needs a password, it fails silently into the existing ignoreError: true fallback path.