migration-seo-paritylisted

# Migration SEO parity check The stage where migrations silently tank traffic. When a site moves, the content can be perfect but rankings still collapse if the SEO signals Google relies on break — broken redirects, changed canonical tags, accidental "noindex", or an inconsistent trailing-slash convention. This skill does two things: 1. **Probes one URL** for the signals that matter, and (if given the old + new URL) compares them and flags mismatches. 2. **Gives the person the full pre-launch cutover checklist** (`references/cutover-checklist.md`) so they know everything to verify before flipping the switch. You (Claude) run this for them. Ask only for a URL (or two). ## How to use it 1. Ask what they're checking: - **One page on the new site** → probe it for SEO health. - **An old page and its new equivalent** → compare the two. 2. Run the probe: ```bash python3 scripts/url-parity-probe.py "<new-url>" # or, to compare old vs new: python3 scripts/url-parity-probe.py "<old-url>" "<new-url>" ``` It reports, per URL: final HTTP status, any redirect chain, the canonical tag, whether the page is indexable (meta robots / X-Robots-Tag), and its trailing-slash form. In compare mode it flags where old and new disagree. 3. Explain the results in plain terms, leading with **anything that will cost rankings**: a page that now says "noindex", a canonical pointing at the wrong URL, a redirect that lands on a 404, or a trailing-slash flip. 4.