feat(analytics): retire Rybbit and add SEO/GEO discovery tracking

Document Umami as the sole analytics platform, remove Rybbit proxy and
tracker code, and classify public page traffic with discovery_channel for
adm SEO/GEO dashboards.

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

server/portal-integration-services-bootstrap.test.mjs

@@ -124,7 +124,6 @@ function createSetup(overrides = {}) {
     },
     sessionSnapshotService,
     mindSpaceAnalyticsConfig: { enabled: true },
-    mindSpaceRybbitConfig: { enabled: true },
     subscriptionService,
     apiTarget: 'http://api',
     apiSecret: 'secret',
@@ -164,10 +163,6 @@ function createSetup(overrides = {}) {
       calls.push(['analytics', event]);
       return Promise.resolve();
     },
-    sendMindSpaceRybbitEventFn(event) {
-      calls.push(['rybbit', event]);
-      return Promise.resolve();
-    },
     createNotificationDispatcherFn(receivedOptions) {
       calls.push(['notification-dispatcher']);
       notificationOptions = receivedOptions;
@@ -425,13 +420,6 @@ test('preserves generated-page analytics projection', async () => {
     analyticsCall[1].generatedAt,
     /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z$/,
   );
-  const rybbitCall = setup.calls.find(
-    ([name]) => name === 'rybbit',
-  );
-  assert.deepEqual(rybbitCall[1], {
-    ...analyticsCall[1],
-    config: { enabled: true },
-  });
 });
 
 test('preserves notification, recharge, reminder, and page-edit wiring', async () => {