Failure mode: canonical tags that point to a redirecting URL

Failure mode: canonical tags that point to a redirecting URL

Most common index-bloat leak we audit: the template emits a canonical to the clean URL, but the clean URL 301s to a tracked or trailing-slash variant. Google sees a canonical that redirects, ignores it, and indexes the messy version.

Fix, run in order:
— Step 1. Owner: SEO. Pull 200 sample URLs, fetch each canonical target, record final status. Gate: every canonical must return 200, never 301/302.
— Step 2. Owner: dev. Normalize the canonical builder to output the exact post-redirect URL (slash, case, params stripped).
— Step 3. Owner: dev. Add a unit test asserting canonical == response URL on a fixture page.
— Step 4. Owner: SEO. Re-fetch the 200 sample after deploy. Gate: zero redirecting canonicals.

Guardrail: a canonical pointing at anything that isn't a live 200 is a build-breaking error, not a warning.

Ship gate: don't publish until all boxes are checked.