ui: point plugin link to etherpad.org/plugins, add scanner link, clearer CTA (#370)

* feat(plugins): sort by downloads descending by default

The /plugins landing previously displayed plugins in the arbitrary
order the \`plugins.viewer.json\` feed happened to serialise them,
which put 2021-era plugins in front of actively-used modern ones.
Visitors landing on the page had no signal about which plugins the
community actually runs.

- Sort the plugin list by monthly download count descending at load
  time, so the top of the page shows the plugins people actually use.
- Surface "Downloads" as an explicit option (and the new default) in
  the sort dropdown, listed first. The sort logic for it already
  existed as the \`setSortKey\` fallback; this just wires it up to a
  visible entry rather than leaving it as the unreachable else branch.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* ui: point plugin link to etherpad.org/plugins, scanner link, clearer CTA

- AI plugins CTA now points to /plugins instead of static.etherpad.org
- WhoUsesEtherpad: drop wiki listing invite; link self-hosted bullet to scanner.etherpad.org
- RealTimeCollaboration: make "Pick one of the publicly available" the full link phrase and inline the anchor

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: JohnMcLear

src/components/RealTimeCollaborationLink.tsx

@@ -25,7 +25,7 @@ export const AIOnYourTerms = () => {
         </p>
 
         <p className="dark:text-gray-400">
-            <a className="underline" href="https://static.etherpad.org" target="_blank">Browse AI plugins &rarr;</a>
+            <a className="underline" href="https://etherpad.org/plugins" target="_blank">Browse AI plugins &rarr;</a>
         </p>
     </div>
 }

src/pagesToDisplay/AIOnYourTerms.tsx

@@ -1,8 +1,6 @@
 import {FontAwesomeIcon} from "@fortawesome/react-fontawesome";
 import {faFingerprint, faShieldHalved, faPuzzlePiece} from "@fortawesome/free-solid-svg-icons";
 
-import {RealTimeCollaborationLink} from "../components/RealTimeCollaborationLink.tsx";
-
 export const RealTimeCollaboration = ()=>{
 
     return <div className="content wrap">
@@ -39,7 +37,7 @@ export const RealTimeCollaboration = ()=>{
         </div>
 
         <p className="mt-8 dark:text-gray-400">
-            You don&apos;t need to set up a server to try it. <RealTimeCollaborationLink/> one of the publicly available instances run by friendly people around the world &mdash; or set up your own by following our <a className="underline" href="https://github.com/ether/etherpad-lite#installation">installation guide</a>.
+            You don&apos;t need to set up a server to try it. <a className="underline" href="#links">Pick one of the publicly available</a> instances run by friendly people around the world &mdash; or set up your own by following our <a className="underline" href="https://github.com/ether/etherpad-lite#installation">installation guide</a>.
         </p>
     </div>
 }

src/pagesToDisplay/RealTimeCollaboration.tsx

@@ -18,11 +18,7 @@ export const WhoUsesEtherpad = () => {
             <li><strong>Universities and schools worldwide</strong> &mdash; including jurisdictions where Google Workspace is no longer permitted in education.</li>
             <li><strong>Civic-tech and democratic-deliberation projects</strong> &mdash; citizen assemblies, participatory budgeting, public consultations.</li>
             <li><strong>Newsrooms and investigative journalism teams</strong> &mdash; where authorship and editing history matter for legal and editorial integrity.</li>
-            <li><strong>Tens of thousands of self-hosted instances</strong> &mdash; run by IT teams who chose Etherpad because it is theirs.</li>
+            <li><strong><a className="underline" href="https://scanner.etherpad.org/" target="_blank">Tens of thousands of self-hosted instances</a></strong> &mdash; run by IT teams who chose Etherpad because it is theirs.</li>
         </ul>
-
-        <p className="dark:text-gray-400 mt-4">
-            If your organisation runs Etherpad and would like to be listed publicly, please <a className="underline" href="https://github.com/ether/etherpad-lite/wiki/Sites-That-Run-Etherpad" target="_blank">add it to the wiki</a>.
-        </p>
     </div>
 }