cherry-pick SEO P1 batches A+B+C → main

src/app/alternatives/[slug]/page.tsx

@@ -128,7 +128,19 @@ export default async function AlternativePage({
         datePublished: getBenchCreatedAt(bench.slug).toISOString(),
         ...(citableAsOf(bench) ? { dateModified: bench.lastRunAt } : {}),
         variableMeasured: bench.metric,
-        isBasedOn: benchUrl,
+        // Cross-doc @id-only refs get validated as standalone
+        // incomplete Datasets by Google (same failure mode as PR #1442's
+        // isBasedOn fix). Inline the required fields per bench.
+        isBasedOn: {
+          "@type": "Dataset" as const,
+          "@id": `${benchUrl}#dataset`,
+          name: bench.title,
+          description: bench.subtitle,
+          url: benchUrl,
+          creator: CREATOR_PUBLISHER,
+          license: DATASET_LICENSE,
+          isAccessibleForFree: true,
+        },
         distribution: [
           {
             "@type": "DataDownload",

src/app/answers/[slug]/page.tsx

@@ -75,14 +75,25 @@ export async function generateMetadata({
       type: "article",
       url,
       siteName: SITE.name,
-      images: [{ url: `${SITE.url}/opengraph-image`, width: 1200, height: 630 }],
+      // Use the referenced bench's OG card instead of the site-wide
+      // default. Perplexity / ChatGPT / Claude Deep Research scrape the
+      // og:image alongside the answer text; showing the bench-specific
+      // leader card gives the AI a real datapoint next to the answer
+      // rather than the generic homepage tile.
+      images: [
+        {
+          url: `${SITE.url}/api/og/${ans.bench.slug}`,
+          width: 1200,
+          height: 630,
+        },
+      ],
     },
     twitter: {
       card: "summary_large_image",
       site: SITE.twitter,
       title,
       description,
-      images: [`${SITE.url}/twitter-image`],
+      images: [`${SITE.url}/api/og/${ans.bench.slug}`],
     },
   };
 }
@@ -182,6 +193,9 @@ export default async function AnswerPage({
     text: ans.question,
     acceptedAnswer: {
       "@type": "Answer",
+      // Google's Rich Results validator flags Answer nodes without a
+      // `name` field (parity with the compare-page FAQPage builder).
+      name: ans.question,
       text: capDescription(shortAnswer, 990),
       url,
       author: { "@id": `${SITE.url}/#org` },
@@ -190,6 +204,7 @@ export default async function AnswerPage({
   if (expertTake) {
     questionNode.suggestedAnswer = {
       "@type": "Answer",
+      name: ans.question,
       text: capDescription(expertTake, 990),
       url,
       author: { "@id": PERSON_ID },
@@ -218,7 +233,16 @@ export default async function AnswerPage({
         author: { "@id": `${SITE.url}/#org` },
         publisher: { "@id": `${SITE.url}/#org` },
         image: `${SITE.url}/api/og/${bench.slug}`,
-        isBasedOn: benchUrl,
+        // Inline the referenced bench Dataset (bare URL ref gets
+        // validated as a standalone incomplete Dataset by Google, same
+        // failure mode as PR #1442's isBasedOn fix).
+        isBasedOn: {
+          "@type": "Dataset",
+          "@id": `${benchUrl}#dataset`,
+          name: bench.title,
+          description: bench.subtitle,
+          url: benchUrl,
+        },
       },
       buildBreadcrumbJsonLd([
         { name: "Home", item: SITE.url },

src/app/benchmarks/[slug]/page.tsx

@@ -165,7 +165,12 @@ export async function generateMetadata({
     },
     other: {
       citation_title: metaTitle,
-      citation_author: "OpenChainBench",
+      // Highwire Press citation_author expects a person name (Scholar
+      // routinely rejects records where author reads as a publisher
+      // organisation). The Person is also anchored in the JSON-LD
+      // Dataset creator + StatisticalReport contributor, so the two
+      // signals agree.
+      citation_author: "Florent Tapponnier",
       citation_publisher: "OpenChainBench",
       ...(isoPubDate ? { citation_publication_date: isoPubDate } : {}),
       citation_doi: "10.5281/zenodo.20800312",
@@ -507,9 +512,24 @@ export default async function BenchmarkPage({
       <h1 className="mt-5 display text-3xl sm:text-4xl md:text-5xl tracking-tight text-ink break-words">
         {benchmark.title}
       </h1>
-      <p className="mt-4 max-w-3xl text-lg sm:text-xl text-ink-muted leading-snug break-words">
-        {benchmark.subtitle}
-      </p>
+      {/* Grounding-line first-under-H1: Perplexity / ChatGPT search /
+          Claude Deep Research scrape the first prose sentence after the
+          H1 as the "citable claim." Previously the methodology-flavoured
+          subtitle sat here; the current-leader sentence carries a
+          concrete provider + number + unit that AI answer engines quote
+          verbatim ("Codex leads head lag at 0.8 s (p50, 24h)..."). Fall
+          back to the subtitle when no defensible leader exists (draft,
+          insufficient, cold start). */}
+      {sentence ? (
+        <p className="mt-4 max-w-3xl text-lg sm:text-xl text-ink leading-snug break-words">
+          <span className="font-medium">{sentence}</span>{" "}
+          <span className="text-ink-muted">{benchmark.subtitle}</span>
+        </p>
+      ) : (
+        <p className="mt-4 max-w-3xl text-lg sm:text-xl text-ink-muted leading-snug break-words">
+          {benchmark.subtitle}
+        </p>
+      )}
 
       {/* Compact "At a glance" card. Rendered as a native <details>
           element so it collapses to a one line summary on click while

src/app/compare/[slug]/page.tsx

@@ -717,12 +717,36 @@ export default async function ComparePage({
     isAccessibleForFree: true,
     license: DATASET_LICENSE,
     measurementTechnique: `${SITE.url}/methodology`,
-    variableMeasured: shared.map((s) => ({
-      "@type": "PropertyValue",
+    // PropertyValue in a Dataset variableMeasured needs a numeric `value`
+    // for Google Dataset Search + academic LLM tools to extract the
+    // structured fact. Fallback to the aggregate winner's p50 in the
+    // shared unit; skip PropertyValue.value entirely when neither side
+    // returned data so we never publish a fabricated zero.
+    variableMeasured: shared.map((s) => {
+      const winner = s.aggregateWinner === "a" ? s.aResult : s.bResult;
+      const v = winner?.p50;
+      return {
+        "@type": "PropertyValue" as const,
+        name: s.title,
+        unitText: s.unit,
+        ...(typeof v === "number" && v > 0 ? { value: v } : {}),
+      };
+    }),
+    // isBasedOn is a cross-doc reference to each bench Dataset. Google
+    // validates each Dataset in isolation and does not stitch bare-URL
+    // refs, so previously flagged them as standalone Datasets without
+    // name/description (same failure mode as PR #1442's isBasedOn fix
+    // in dataset-jsonld.ts). Inline the required fields per bench.
+    isBasedOn: shared.map((s) => ({
+      "@type": "Dataset" as const,
+      "@id": `${SITE.url}/benchmarks/${s.slug}#dataset`,
       name: s.title,
-      unitText: s.unit,
+      description: `${s.metric} (${s.unit}) benchmark on OpenChainBench: live measurements for ${a.name} and ${b.name}.`,
+      url: `${SITE.url}/benchmarks/${s.slug}`,
+      creator: CREATOR_PUBLISHER,
+      license: DATASET_LICENSE,
+      isAccessibleForFree: true,
     })),
-    isBasedOn: shared.map((s) => `${SITE.url}/benchmarks/${s.slug}`),
     distribution: shared.map((s) => ({
       "@type": "DataDownload",
       encodingFormat: "application/json",
@@ -772,6 +796,9 @@ export default async function ComparePage({
   const faqJsonLd = {
     "@context": "https://schema.org",
     "@type": "FAQPage",
+    // GSC's Rich Results tester flags FAQPage nodes without an `@id`
+    // (every other FAQPage on the site emits one via the shared builder).
+    "@id": `${url}#faq`,
     // Google's Rich Results validator flags missing `name` on the
     // FAQPage parent even when Question.name is set. Add here + on
     // Answer nodes so the compare page matches the shared FAQ builder
@@ -885,6 +912,32 @@ export default async function ComparePage({
         </div>
       </section>
 
+      {/* Visible FAQ parity with the FAQPage JSON-LD above. Google
+          requires visible Q&A text matching the schema entries or it
+          silently drops the rich result — the compare pages had FAQ
+          jsonld without any visible questions, so the FAQPage never
+          rendered in the SERP snippet. */}
+      <section className="mt-12 max-w-3xl">
+        <h2 className="text-[11px] font-medium uppercase tracking-[0.18em] text-ink-muted">
+          Frequently asked questions
+        </h2>
+        <div className="mt-4 space-y-4">
+          {faqEntries.map((e) => (
+            <details
+              key={e.q}
+              className="border border-rule rounded-lg px-4 py-3"
+            >
+              <summary className="cursor-pointer text-sm font-medium text-ink leading-tight">
+                {e.q}
+              </summary>
+              <p className="mt-3 text-sm leading-relaxed text-ink-soft">
+                {e.a}
+              </p>
+            </details>
+          ))}
+        </div>
+      </section>
+
       <section className="mt-12 max-w-3xl">
         <h2 className="text-[11px] font-medium uppercase tracking-[0.18em] text-ink-muted">
           How this pair was selected

src/app/products/[slug]/page.tsx

@@ -16,6 +16,7 @@ import {
 import { Breadcrumb } from "@/components/breadcrumb";
 import { buildBreadcrumbJsonLd, safeJsonLd } from "@/lib/jsonld";
 import { CREATOR_PUBLISHER, CITABLE_JSON_URL, DATASET_LICENSE } from "@/lib/dataset-jsonld";
+import { getBenchCreatedAt } from "@/lib/seo/bench-dates";
 import {
   fetchHlBuilderStats,
   isHlBuilderSlug,
@@ -446,9 +447,18 @@ export default async function ProviderPage({
         ...(sameAs.length > 0 ? { sameAs } : {}),
         subjectOf: sorted.map((a) => ({
           "@type": "Dataset",
+          // GSC + Google Dataset Search flag anonymous Datasets
+          // ("Unnamed item" with recommended fields missing) when the
+          // @id + datePublished are absent (audit 2026-07-26). Match
+          // the shape used by the bench page's own Dataset node so
+          // cross-page identifiers align.
+          "@id": `${SITE.url}/benchmarks/${a.benchmark.slug}#dataset`,
           name: a.benchmark.title,
           description: capDescription(a.benchmark.subtitle, 990),
           url: `${SITE.url}/benchmarks/${a.benchmark.slug}`,
+          identifier: a.benchmark.slug,
+          variableMeasured: a.benchmark.metric,
+          datePublished: getBenchCreatedAt(a.benchmark.slug).toISOString(),
           creator: CREATOR_PUBLISHER,
           publisher: CREATOR_PUBLISHER,
           isAccessibleForFree: true,