prometheus: SEO terms in the Browsers & web tools blurb

Readers searching for "web3 browsers" or "decentralized domain names"
weren't finding the Browsers & web tools category because the blurb
only talked about BCNR, which almost nobody types into a search box.

Blurb reworded to:
  Web3 browsers and decentralized domain name resolvers. BCNR tooling
  that teaches Chrome, Firefox and other browsers to reach .x and the
  other decentralized TLDs.

Same category, same scope — new terms up front so a crawler reading
the sub-chip on /t/apps, the category hero on /c/browsers, or the
<meta description> on either page sees the words a web3-curious reader
would type to find it. The listing cards for Ariadne's Thread, Ariadne
Navigator and Theseus Navigator inside the category pick up the SEO
value by association.

Single file: the blurb lives once in CATEGORIES and propagates to
every surface that renders it.

service/pages-browse.js

@@ -50,7 +50,7 @@ const TOP_BY_SLUG = Object.fromEntries(TOP_CATEGORIES.map((t) => [t.slug, t]));
 export const CATEGORIES = [
   // ===== Apps sub-categories =====
   { slug: 'browsers',      top: 'apps', icon: '/static/icons/cat-browsers.svg',      title: 'Browsers & web tools',
-    blurb: `BCNR resolvers, mobile browsers, extensions that teach other browsers to speak .x and the other decentralized TLDs.` },
+    blurb: `Web3 browsers and decentralized domain name resolvers. BCNR tooling that teaches Chrome, Firefox and other browsers to reach .x and the other decentralized TLDs.` },
   { slug: 'communication', top: 'apps', icon: '/static/icons/cat-communication.svg', title: 'Communication',
     blurb: `Messengers, voice, boards, group chats. Clients that route through peers rather than someone else's server.` },
   { slug: 'privacy',       top: 'apps', icon: '/static/icons/cat-privacy.svg',       title: 'Privacy & security',