fix: report ok for silent npm scripts

[sdwolf4103]

Summary

• Treat npm 7+ leading lifecycle echo lines as boilerplate so successful silent scripts fall back to ok.
• Preserve substantive script output, including > lines after real output and a single leading > line that may be user output.
• Add regression tests for lifecycle-only output and over-filtering edge cases.

Verification

• git diff --check -- src/cmds/js/npm_cmd.rs
• Static logic verification of the added npm filter cases

Note: local environment did not have cargo/rustc, so Rust tests should run in CI.

[CLAassistant]

All committers have signed the CLA.

[pszymkowiak]

[w] wshm · Automated triage by AI

📊 Automated PR Analysis

🐛 Type	bug-fix
🟡 Risk	medium

Summary

This PR fixes the npm output filter to treat npm 7+ leading lifecycle echo lines (e.g. script name and command) as boilerplate, so that silent scripts with no substantive output correctly report "ok". It preserves a single leading "> " line as possible user output and keeps "> " lines that appear after real output. Regression tests cover lifecycle-only output, substantive output preservation, and edge cases.

Review Checklist

• Tests present
• Breaking change
• Docs updated

---

Analyzed automatically by wshm · This is an automated analysis, not a human review.