Improve SEO and social card wiring

Add SearchAction and optional Product JSON-LD, per-page OG images/alts, and document the og build and cache headers.

Co-authored-by: Cursor <cursoragent@cursor.com>

web/src/pages/[...locale]/fedimint/[id].astro

@@ -34,6 +34,7 @@ import { ogImageFor } from '../../../lib/og';
 import { fedimintSubject } from '../../../lib/review-subject';
 import { breadcrumbNode, mintServiceNode } from '../../../lib/schema';
 import { clampWords, cleanMintDescription, isIndexableMint, nameCollisions, seoName } from '../../../lib/seo';
+import { PRODUCT_JSONLD } from '../../../lib/site';
 import { bannerHtml } from '../../../lib/mint-state';
 import { localModuleName, localNetworkName, moduleRowsHtml, otherModules } from '../../../lib/fedimint-ui';
 import { iconGradient, initials, transitionName, truncateMiddle } from '../../../lib/format';
@@ -197,6 +198,7 @@ const schema = [
     canonical,
     name: titleName,
     description,
+    product: PRODUCT_JSONLD,
     /*
      * The invite code stands in for the service's address, because it is the address:
      * it is the string a wallet is given to reach this federation. A federation with no
@@ -217,11 +219,13 @@ const schema = [
 ---
 
 <Base
-  title={t('fedimint.title', { name: titleName })}
+  title={title}
   description={description}
   current="fedimints"
   noindex={!indexable}
   schema={schema}
+  image={ogImage ?? undefined}
+  imageAlt={imageAlt}
 >
   <div class="page">
     <nav class="crumbs" aria-label={t('fedimint.breadcrumb')}>

web/src/pages/[...locale]/mint/[host].astro

@@ -15,6 +15,7 @@ import { ogImageFor } from '../../../lib/og';
 import { mintSubject } from '../../../lib/review-subject';
 import { breadcrumbNode, mintServiceNode } from '../../../lib/schema';
 import { clampWords, cleanMintDescription, isIndexableMint, nameCollisions, seoName } from '../../../lib/seo';
+import { PRODUCT_JSONLD } from '../../../lib/site';
 import { bannerHtml, limitsHtml, localNutName, nutRowsHtml } from '../../../lib/mint-state';
 import {
   displayDomain, iconGradient, initials, shortNpub, transitionName, truncateMiddle,
@@ -185,9 +186,13 @@ const title =
  * the plain status, and the limits are only quoted for a mint that can actually take
  * a deposit.
  */
+// A mint with no name of its own (titleName fell back to the domain) gets the
+// domain-only sentence, not "Community reviews for {domain} ({domain})".
 const lead =
   cleanMintDescription(mint.description) ??
-  t('seo.desc.fallback', { name: titleName === domain ? name : titleName, domain });
+  (titleName === domain
+    ? t('seo.desc.fallbackDomain', { domain })
+    : t('seo.desc.fallback', { name: titleName, domain }));
 
 const ratingPart = hasRating
   ? t('seo.desc.rated', { rating: f.decimal(mint.rating_avg!), n: mint.review_count })
@@ -251,6 +256,7 @@ const schema = [
     name: titleName,
     description,
     mintUrl: mint.url,
+    product: PRODUCT_JSONLD,
     icon: icon ? new URL(icon, Astro.site).href : null,
     /*
      * Only when reviews actually carried ratings. `ratedCount` is what produced the