seo-social-cards (M8)

Social cards control how a URL renders when shared on social, chat, and AI assistants — a CTR/sharing signal, not a ranking one (see Honesty). Open Graph metadata is the same <head>-level hygiene tier as the structured-data work in references/schema-tier1.md, so audit it alongside that module.

Audits

Working from the PageSnapshot (rendered_dom if present, else raw_html):

OG content: og:title, og:description, og:url, og:type present and non-empty; og:url matches the canonical; og:type sane for the page (e.g. article vs website).
OG image: og:image present, ~1200x630 (1.91:1) and >=200x200, and reachable (HTTP 200, image content-type, absolute URL).
Twitter/X: twitter:card (prefer summary_large_image); twitter:title, twitter:description, twitter:image. Twitter falls back to OG when these are absent — note when it is relying on OG.
Fallback behavior: when OG is absent entirely, record what crawlers would derive (<title>, meta description, first content <img>) so the finding shows the actual degraded card, not a guess.

Fixes

AUTO (fixable: auto): inject a complete OG + Twitter card block derived from the page's <title>/<h1>, meta description, canonical URL, and first in-content image. Additive, deterministic, emitted as a diff for fix.
The tool cannot create an image asset. It wires og:image/twitter:image once a real path exists; until then it leaves a clearly-marked TODO placeholder (no invented URL or dimensions). Never fabricate title/description text — derive from on-page content or leave the user a TODO.

Verification

dom_assert: the required <meta property="og:*"> / <meta name="twitter:*"> tags exist and are non-empty.
header_check: og:image returns 200 with an image content-type, and dimensions are ~1200x630.
When the image fetch or dimension probe is blocked (no network/egress), status is needs_api, never a false pass.