feat(settings): retire the third-party plugin integrations

Settings → Integrations offered install cards for the Claude Code and
Cursor provider plugins. They are gone: the section, its plugin catalog,
its own i18n module and tests, the settings search entries, the page
keywords, and the two sprite icons only it used. The page now holds the
built-in GitHub and Linear cards, so it is hidden in VS Code where neither
applies; its title and description live in the settings dictionaries.

Docs follow: the Integrations page in every locale now documents GitHub
(pointing at its own page) and Linear in full, the GitHub page names
Settings → Integrations as the place to connect and covers linking an
issue or PR to a message, and the Providers pages no longer promise Claude
or Cursor subscriptions.

Claude-Session: https://claude.ai/code/session_01HB9wdLQoZX2vfyDjwv6Rso

packages/ui/src/components/views/SettingsView.tsx

@@ -310,24 +310,6 @@ export const SettingsView: React.FC<SettingsViewProps> = ({ onClose, forceMobile
     setMobileStage(def.kind === 'split' ? 'page-sidebar' : 'page-content');
   }, [isMobile, setSettingsPage]);
 
-  const openThirdPartyProviderSetup = React.useCallback(async (providerId: string): Promise<boolean> => {
-    const configStore = useConfigStore.getState();
-    await configStore.loadProviders({ source: 'settings:third-party-provider-setup' });
-    const providerAvailable = useConfigStore.getState().providers.some(
-      (provider) => provider.id === providerId,
-    );
-    if (!providerAvailable) {
-      return false;
-    }
-
-    configStore.setSelectedProvider(providerId);
-    openPage('providers');
-    if (isMobile) {
-      setMobileStage('page-content');
-    }
-    return true;
-  }, [isMobile, openPage]);
-
   const activePageMeta = React.useMemo(() => {
     return getSettingsPageMeta(settingsSlug);
   }, [settingsSlug]);
@@ -679,12 +661,7 @@ export const SettingsView: React.FC<SettingsViewProps> = ({ onClose, forceMobile
       case 'git':
         return <GitPage />;
       case 'integrations':
-        return (
-          <IntegrationsPage
-            onOpenProviderSetup={openThirdPartyProviderSetup}
-            onOpenPluginManager={() => openPage('plugins')}
-          />
-        );
+        return <IntegrationsPage />;
       case 'general':
       case 'appearance':
       case 'chat':
@@ -700,7 +677,7 @@ export const SettingsView: React.FC<SettingsViewProps> = ({ onClose, forceMobile
       default:
         return null;
     }
-  }, [openChamberSectionBySlug, openPage, openThirdPartyProviderSetup, renderUnavailable, runtimeCtx, t]);
+  }, [openChamberSectionBySlug, renderUnavailable, runtimeCtx, t]);
 
   // Mobile: if opened via deep-link / palette to a non-home page, jump into it once.
   React.useEffect(() => {