[rahul05ranjan]

Fixes #82

What changed

--stale-days is validated before anything runs. A flag given as the last argument arrives as undefined and a non-number as NaN; either used to slip through and the run died later in new Date(NaN).toISOString() — after every fetch had already run. parseStaleDays (now in site/lib/link-check.mjs, next to the other pure parts of the script) rejects anything that is not a whole number of days ≥ 0, and the script prints the reason plus a usage line and exits 2 immediately:

$ node site/check-links.mjs --stale-days abc
--stale-days wants a whole number of days >= 0, got "abc"
usage: node site/check-links.mjs [--report <file.md>] [--stale-days 365]

API failures are never catalog problems. checkMaintenance moved to site/lib/link-check.mjs (with an injectable fetch so the classification is testable) and returns { differs, skipped }. A 5xx, a timeout or a rate limit produces a skipped row in a new ### Could not check (GitHub API failures, N) report section, excluded from problems, so a transient outage no longer opens or updates the correction issue. After a 403/429 the loop still stops — but the remaining repositories are each marked not checked: stopped after GitHub API HTTP 403 instead of silently disappearing. Non-github.com entries are never sent to the API (same as before). The summary line now also reports the skipped count, e.g. ... 2 maintenance, 3 API-unchecked, 5 blocked.

The report wording for genuine maintenance mismatches, the blocked section, the --report path and the problems= workflow output are unchanged, except that problems no longer includes API failures.

Verification (system Node v26.12.1, no installs)

• node site/lib/lib.test.mjs: 425 ok (404 before; 21 new assertions) — parseStaleDays (365, 0, abc, undefined, -5, 3.5) and checkMaintenance with a fake fetch: 5xx → skipped not problem; a genuine archived-repo mismatch → differs; 403 stops the loop, 1 call, remaining repos reported with the reason; a thrown fetch error → skipped; non-github entries make zero API calls.
• node site/checks.test.mjs: 134 ok (unchanged — no regressions).
• node --check site/check-links.mjs / site/lib/link-check.mjs: OK.
• Live CLI check: --stale-days abc and a trailing --stale-days both exit 2 with the message and usage before any network activity (no catalog fetches run; the validation precedes loadEntries).
• Could not run a real link check (it fetches 414 external sites; not appropriate here).

AI-assisted implementation and self-review.

[TMHSDigital]

Thank you for this, and for the tests. #124 merged this morning with the same fix for #82 (opened before this PR could be reviewed), so this branch now conflicts with main and the issue is closed. I compared the two line by line and main covers everything here, so I am closing this as superseded rather than asking for a rebase. Contributions are welcome on any of the remaining open issues.